(10/8/17)

CHAPTER 1

WHAT IS FOREIGN RELATIONS LAW?

CURTIS A. BRADLEY*

[THE OXFORD HANDBOOK OF COMPARATIVE FOREIGN

RELATIONS LAW (Curtis A. Bradley ed., forthcoming 2018)]

This first chapter considers what is potentially encompassed by the term “foreign
relations law,” and what it might mean to think about it as a distinct field of law that can
be compared and contrasted across national jurisdictions. The chapter begins by
outlining some differences between foreign relations law and international law. It then
describes the development of foreign relations law as a field of study within the United
States and considers why, at least until recently, it has not been treated as a field in most
other countries. Finally, the chapter highlights a central question for foreign relations
law, which is the extent to which it (or at least some parts or elements of it) should be
treated differently than other types of domestic law—a debate referred to in the United
States as one over “foreign affairs exceptionalism.”

I. FOREIGN RELATIONS LAW AND INTERNATIONAL LAW

Before comparing and contrasting the foreign relations law of various nations, we
first need to have a sense of what, precisely, we mean by “foreign relations law.” For
purposes of the book, the term is used to encompass the domestic law of each nation that
governs how that nation interacts with the rest of the world.1 These interactions include
most centrally those interactions that occur between nations, but they can also encompass
interactions between a nation and the citizens or residents of other nations and with
international institutions. The law governing these interactions can take a variety of
forms, including constitutional law (written and unwritten), statutory law, administrative

*
William Van Alstyne Professor, Duke Law School. I would like to thank Gib van Ert, Shaheed
Fatima, and Ralf Michaels for their helpful comments on this chapter. I also benefitted from discussions
with my students in a course on comparative foreign relations law that I taught as part of the Duke-Geneva
Institute in Transnational Law.
1
As noted below, the European Union, as a supranational institution that in some ways resembles
a nation, also has a developed body of foreign relations law.
 2

regulations, and judicial decisions. Because many disputes concerning foreign relations
law are addressed outside the courts, a full study of the topic also requires attention to
domestic “conventions” of proper political behavior that may or may not have legal
status.

Many issues of foreign relations law concern allocations of authority between

political actors, such as the authority to represent the nation in diplomacy, to conclude
and terminate international agreements, to recognize foreign governments and their
territories, and to initiate or end the use of military force. In federal systems, these
allocation issues are not only horizontal but also vertical, extending to the relations
between national and sub-national institutions. But foreign relations law also
encompasses issues relating to the role of the courts in transnational cases, such as
whether certain issues are “nonjusticiable” and thus subject entirely to political branch
determination, whether courts should take into account considerations of international
comity when interpreting and applying domestic law, and whether and to what extent
courts can apply international law directly to decide a particular case. Because much of
foreign relations law addresses how authority is allocated among governmental actors, its
topics are most salient for constitutional democracies that separate power and have
independent judiciaries (and such democracies are the principal focus of this book), but
the topics also have some relevance to other forms of government.2

For the purposes of this book, the term “foreign relations law” is not meant to
encompass “pure” questions of international law—that is, a nation’s obligations under
treaties and customary international law on the international plane. While such
international law governs in part how a nation conducts its foreign relations, it is both too
vast, and in many respects too undifferentiated in its application to each nation, to be
included in a working definition that will be useful for a study of comparative foreign
relations law. So, when this book refers to foreign relations law, it is referring to various
forms of domestic law.

To be sure, nations have differing international law obligations, and that fact is of
potential comparative interest. Perhaps most obviously, nations have differing treaty
commitments. These variations in commitments can exist even for customary
international law, since it is possible that some nations will have opted out of particular
rules through persistent objection, or that particular sets of nations are subject to
“regional custom.” In addition, even when international law obligations are ostensibly
equal, nations may interpret them differently. Given the limits on centralized
international adjudication, these differences of interpretation will often persist. While it
may be fruitful to study differing national approaches to international law, and there are
projects that attempt to do so,3 this book involves a different project.

2
For additional discussion of some of the potential functions served by foreign relations law, see
Campbell McLachlan, Five Conceptions of the Function of Foreign Relations Law (draft chapter for this
volume).
3
See, e.g., Anthea Roberts, Paul B. Stephan, Pierre Hugues-Verdier, and Mila Versteeg,
Comparative International Law: Framing the Field, 109 AM. J. INT’L L. 467 (2014).
 3

This book recognizes, however, that there are important interconnections between
international law and foreign relations law. Some international law is converted into
domestic law, either by the courts or through legislative or executive branch directive.
Moreover, even when international law is not incorporated into a domestic legal system,
courts may construe domestic law in light of international legal obligations, and the
executive branch may exercise its discretion in light of such obligations.4 At times,
courts may even do the opposite and construe international law in light of domestic law.
(A domestic court might presume when construing a treaty, for example, that in making
the treaty its government would not have intended to override certain aspects of domestic
law.) This book’s definition of foreign relations law includes the domestic rules
governing these interconnections, but not the substance of the underlying international
law.5

A country’s foreign relations law can also have important effects on the content
and operation of international law. Foreign relations law can influence how nations form
treaties and what they agree to in treaties, and it can also affect the state practice that
forms the foundation for rules of customary international law. In addition, by regulating
allocations of domestic authority, foreign relations law can affect a nation’s compliance
with international law because different domestic institutions may have differing levels of
commitment to (or capacity for) ensuring compliance.

As illustrations of the distinction between international law and foreign relations

law, consider these seven examples, involving different countries and different types of
domestic law:

Ÿ In 2017, the Supreme Court of Ghana held that Ghana’s president had acted
unconstitutionally in concluding an agreement with the United States to receive and
resettle two detainees who had been held by the United States at the Guantanamo Bay
naval base.6 The court reasoned that Article 75 of Ghana’s constitution required that such
an agreement be approved by the Parliament, and the court expressly distinguished
Ghana’s constitutional law and practice concerning treaty-making from that of the United
States.

4
In the United States, courts apply the “Charming Betsy” canon of construction, whereby federal
statutes are construed, where possible, so that they do not violate international law. See Murray v. The
Schooner Charming Betsy, 6 U.S. (2 Cranch) 64, 118 (1804) (“[A]n act of Congress ought never to be
construed to violate the law of nations if any other possible construction remains . . . .”). Many other
countries have a similar canon of construction. See ANDRÉ NOLLKAEMPER, NATIONAL COURTS AND THE
INTERNATIONAL RULE OF LAW 73-81 (2011).
5
See also Thomas Giegerich, Foreign Relations Law (Jan. 2011), in MAX PLANCK ENCYCLOPEDIA
OF PUBLIC INTERNATIONAL LAW, at http://opil.ouplaw.com/view/10.1093/law:epil/9780199231690/law-
9780199231690-e937 (“The concrete form and content of a State’s foreign relations law is within its
domestic jurisdiction and thus beyond the range of international law. . . . Nevertheless, international law
cannot be completely indifferent to the foreign relations law of its subjects, which, after all, forms the legal
link connecting their internal to the international sphere.”).
6
See Banful v. Attorney General, J1/7/2016, [2017] GHASC 10 (June 22, 2017), at
https://ghalii.org/gh/ judgment/supreme-court/2017/10-10.
 4

Ÿ Also in 2017, the Supreme Court of the United Kingdom held that the UK
government was required to obtain authorization from Parliament before it could initiate
withdrawal from the European Union.7 The Court reasoned that withdrawal would result
in “a fundamental change in the constitutional arrangements of the United Kingdom,”
and that such a change “must be affected in the only way that the UK constitution
recognises, namely by Parliamentary legislation.”8 The Court was addressing only UK
constitutional law, not the international law governing withdrawal from the EU, which is
regulated by Article 50 of the Treaty on European Union.

Ÿ In 2010, the Supreme Court of Canada held in Canada (Prime Minister) v.

Khadr that, although the United States was violating a Canadian citizen’s rights by
holding him at the Guantánamo Bay detention facility, how Canada should respond to
this violation was a matter for determination by the executive branch, not the courts.9
The court therefore declined to order the Canadian executive branch to request the
citizen’s repatriation to Canada. The court based its decision on “the separation of
powers and the well-grounded reluctance of courts to intervene in matters of foreign
relations.”10

Ÿ Also in 2010, the United Kingdom enacted a statute that, for the first time,
gives Parliament the formal authority to block the ratification of treaties. Although the
UK has long had a constitutional convention—known as the “Ponsonby Rule”—whereby
treaties will be laid before Parliament for a period of time prior to ratification, Part 2 of
the Constitutional Reform and Governance Act of 2010 gives the House of Commons the
authority to indefinitely block ratification.11

Ÿ In 2008, the U.S. Supreme Court held in Medellín v. Texas that the U.S.
obligation under Article 94 of the United Nations Charter to comply with decisions of the
International Court of Justice (ICJ) was not “self-executing” in the U.S. legal system and
thus that an ICJ decision could not be applied to override domestic law absent
congressional implementation of the decision.12 The court did not question that the ICJ
decision was binding on the United States as a matter of international law.

7
R v. Secretary of State for Exiting the European Union, [2017] UKSC 5, at
https://www.supremecourt.uk/cases/docs/uksc-2016-0196-judgment.pdf.
8
Id., para. 82.
9
[2010] 1 SCR 44, at https://scc-csc.lexum.com/scc-csc/scc-csc/en/item/7842/index.do.
10
Id., para. 2.
11 See
Arabella Lang, Parliament’s Role in Ratifying Treaties (House of Commons Library,
Briefing Paper No. 5855, Feb. 17, 2017).
12
552 U.S. 491, 508-09 (2008).
 5

Ÿ In 2005, Germany enacted a Parliamentary Participation Act to regulate the

use of its armed forces.13 Under the Act, the executive branch is generally required to
obtain legislative authorization before deploying armed forces, and the Act specifies in
detail the information that the executive must provide to the Bundestag in its requests for
authorization. The Act does not address the circumstances under which such
deployments are consistent with international law governing the use of force.

Ÿ Since 1973, Japan’s executive branch has followed the “Ohira Principles” in
deciding whether to seek legislative approval of international agreements, named after the
foreign minister who initially promulgated them.14 Under these principles, which might
be viewed as a non-binding “constitutional convention,”15 legislative approval is to be
sought in three general circumstances: (1) when new legislation will be needed or
existing legislation will have to be maintained in order to comply with the agreement, (2)
when the agreement affects fiscal obligations, and (3) when the agreement involves
politically important obligations. These principles do not purport to determine whether
an agreement is binding on Japan as a matter of international law.

In each of these examples, the relevant domestic law, whether in the form of a
constitutional provision, statute, judicial doctrine, or customary practice, regulates how
the nation interacts with the rest of the world, but the law does not itself purport to
determine the nation’s international rights or duties. Such law is what this book refers to
as foreign relations law. There are important commonalities and variations in this foreign
relations law across national jurisdictions, even among developed democracies, and those
commonalities and variations are the focus of this book. This book also explores whether
there are general trends in foreign relations law—for example, a growth in legislative
involvement in foreign relations decisionmaking (such as with respect to treaty-making,
treaty withdrawal, or the use of military force), or an increasing use of international law
by domestic courts to constrain executive authority.

It is important to note that, even though the focus of foreign relations law is on
domestic law rather than international law, there is nothing inherent in such a focus that
requires valuing domestic law over international law or resisting the domestic
incorporation of international law. Nations vary in the extent to which their foreign
relations law places them on the “monist” or “dualist” ends of the spectrum with respect
to the incorporation of international law.16 Domestic doctrines that call for the direct

13
For an English translation, see Memorandum by Dr. Katja S. Ziegler, Annex II to The Model of
a “Parliamentary Army” Under the German Constitution, at https://www.publications.parliament.uk/pa/
ld200506/ldselect/ldconst/236/5120707.htm.
14
See Tadaatsu Mori, The Making and Application of Treaties and Other International
Agreements (discussion paper for Duke-Japan Conference on Comparative Foreign Relations Law).
15
Constitutional conventions are “maxims, beliefs, and principles that guide officials in how they
exercise political discretion.” Keith E. Whittington, The Status of Unwritten Constitutional Conventions in
the United States, 2013 U. ILL. L. REV. 1847, 1860.
16
See generally CURTIS A. BRADLEY, INTERNATIONAL LAW IN THE U.S. LEGAL SYSTEM xii (2d ed.
2015); Pierre-Hugues Verdier & Mila Versteeg, International Law in National Legal Systems: An
Empirical Investigation, 109 AM. J. INT’L L. 514 (2015).
 6

incorporation of treaties or customary international law into the domestic legal system, or
that give international law primacy over some forms of domestic law, or that look to
international law when interpreting domestic law, are themselves part of foreign relations
law.

There are many reasons why the content of foreign relations law might vary even
among constitutional democracies. Countries have differing constitutional histories. It
would not be surprising, for example, to find differences between constitutional
arrangements developed after World War II and those developed earlier. Parliamentary
and presidential systems may have also somewhat different approaches to questions of
the separation of powers.17 In addition, understandings of the judicial role might differ
among countries, including as between civil law and common law countries (as well as
those countries that have a mix of civil and common law). The particular domestic
politics of a country can also have an important influence on the content of its domestic
law, including its foreign relations law. Finally, if foreign relations law is affected by a
nation’s geopolitical status, this will obviously vary, both among individual countries and
over time. Despite these points, differences in foreign relations law also sometimes
reflect differences in policy choices, and an awareness of both the existence and potential
ramifications of such choices can be illuminating for nations when evaluating their own
foreign relations law.

II. FOREIGN RELATIONS LAW AS A “FIELD”

At least until recently, what this book is defining as foreign relations law was not
thought of as a “field” of study outside the United States. Instead, in most countries, it
was thought that there were various fields of domestic law, such as constitutional law and
administrative law, and that these fields sometimes had international components. These
domestic fields, in turn, were sharply distinguished from the field of international law,
both analytically and in terms of the individuals who focused on them.

Like the character in the Molière play who discovers that he has been speaking
prose all his life without realizing it, these nations of course have had foreign relations
law even if they did not describe it as a field. Most obviously, foreign relations law as
defined by this book encompasses a lot of the law that is practiced, and has long been
practiced, by lawyers in foreign ministries. But unlike in the United States, most nations
did not treat it as a discrete field of study.18

17
Cf. Miriam Fendius Elman, Unpacking Democracy: Presidentialism, Parliamentarism, and
Theories of Democratic Peace, 9 SECURITY STUDIES 91, 93 (2000) (discussing “how presidential,
coalitional parliamentary, Westminster parliamentary, and semipresidential democratic systems . . .
influence the autonomy of foreign policymakers, and pose different sets of constraints and opportunities for
foreign security policy making”).
18
Germany may be a partial exception. “Staatsrecht [Law of the State] III” encompasses that
country’s constitutional law relating to external relations, as well as the incorporation of international law
within the German legal system.
 7

That is starting to change. In 2014, Campbell McLachlan—one of the authors for

this volume—published an extensive treatise on Commonwealth foreign relations law.19
This is an important volume, and it was cited in the UK Supreme Court’s decision
concerning Brexit. There have also been recent books on the foreign relations law of the
European Union, which address issues such as the process for concluding international
agreements and the role of federalism that are somewhat comparable to the foreign
relations law issues confronted by individual nations.20 Some non-U.S. universities are
also starting to offer courses on foreign relations law.21

The United States never actually had a monopoly on the field anyway. One
substantial component of foreign relations law concerns the role of domestic courts in
applying international law and in adjudicating transnational cases that implicate
governmental interests. That topic has long received attention outside the United States.
The British scholar and lawyer Cyril Picciotto published a study of the relationship
between international law and both British law and U.S. law in 1915.22 The British
lawyer F.A. Mann was writing about the topic as early as the 1940s, long before he
published his 1986 volume on Foreign Affairs in English Courts.23 There also has been
some recent focus in other countries on how federalism can affect allocations of foreign
relations authority.24

19
See CAMPBELL MCLACHLAN, FOREIGN RELATIONS LAW (2014).
20
MARISE CREMONA AND BRUNO DE WITTE, EU FOREIGN RELATIONS LAW: CONSTITUTIONAL
FUNDAMENTALS (2008); ROBERT SCHüTZE, FOREIGN AFFAIRS AND THE EU CONSTITUTION (2014); see also
BART VAN VOOREN AND RAMSES A. WESSEL, EU EXTERNAL RELATIONS LAW: TEXT, CASES AND
MATERIALS (2014).
21
See, e.g., Foreign Affairs and the Canadian Constitution (David Dyzenhaus and Karen Knop),
University of Toronto School of Law, at https://www.law.utoronto.ca/course/foreign-affairs-and-canadian-
constitution-0; Foreign Relations Law in Comparative Perspective (Roland Portmann), University of St.
Gallen, at http://tools.unisg.ch/Handlers/public/CourseInformationSheet.ashx?
Semester=FS17&EventNumber=8,492,1.00; Foreign Relations Law (Campbell McLachlan), Victoria
University of Wellington, http://www.victoria.ac.nz/courses/laws/547/2017/offering?crn=8592; Foreign
Relations Law (Joris Larik), University of Leiden, at
https://studiegids.leidenuniv.nl/courses/show/63049/Foreign-Relations-Law. For courses on EU Foreign
Relations Law, see, for example, University of Amsterdam, at
http://studiegids.uva.nl/web/uva/sgs/en/c/9964.html; European University Institute, at
http://www.eui.eu/DepartmentsAndCentres/Law/ResearchAndTeaching/
ResearchThemes/Cremona/ConstitutionalFoundationsEUForeignRelationsLaw.asp.
22
See CYRIL M. PICCIOTTO, THE RELATION OF INTERNATIONAL LAW TO THE LAW OF ENGLAND
AND OF THE UNITED STATES OF AMERICA (1915). See also H. Lauterpacht, Is International Law Part of the
Law of England?, 25 TRANSACTIONS OF GROTIUS SOCIETY 51 (1939).
23
See, e.g., F.A. Mann, The Sacrosanctity of the Foreign Act of State, 59 L.Q. REV. 42 (1943).
For a more recent volume concerning international law in British courts, see SHAHEED FATIMA, USING
INTERNATIONAL LAW IN DOMESTIC COURTS (2005). For a study of international law within the U.S. legal
system, see BRADLEY, INTERNATIONAL LAW IN THE U.S. LEGAL SYSTEM, supra note 16. For discussion of
international law in Canadian courts, see GIB VAN ERT, USING INTERNATIONAL LAW IN CANADIAN COURTS
(2d ed. 2008). Some comparative studies of aspects of foreign relations law have emerged in recent years.
See, e.g., THE ROLE OF DOMESTIC COURTS IN TREATY ENFORCEMENT: A COMPARATIVE STUDY (David
Sloss ed., 2009).
24
See, e.g., FOREIGN RELATIONS IN FEDERAL COUNTRIES (Hans Michelmann ed., 2009).
 8

It is not entirely clear why the field of foreign relations law has a much more
extensive history in the United States than in other countries. The United States has the
oldest written Constitution in the world, and accommodating that Constitution to a
radically changed international environment, as well as a substantially different U.S. role
in that environment, may present unique challenges. The Constitution’s inclusion of
treaties in the Supremacy Clause, which infuses a degree of monism into U.S.
constitutional law, may also present particular challenges for U.S. law, especially as
treaty-making has changed over time. In addition, the United States has a unique brand
of federalism that tends to generate difficult legal issues as globalization has blurred the
line between foreign and domestic affairs. Law schools in the United States also may
have a more flexible structure than in many other countries, allowing faculty to more
easily cross historic subject matter divides. Finally, many internationally-focused U.S.
academics have experience in the Legal Adviser’s Office of the State Department, the
work of which is often centered around foreign relations law.

Nor is it clear when to date the emergence of such a field in the United States.
One might be tempted to date it to Louis Henkin’s magisterial treatise, Foreign Affairs
and the Constitution, the first edition of which was published in 1972.25 Since then, U.S.
casebooks specifically dedicated to the study of foreign relations law emerged: initially
the Franck and Glennon casebook, the first edition of which was published in 1987,26 and
then the Bradley and Goldsmith casebook, the first edition of which was published in
2002.27 There have also been a number of additional monographs on the topic.28

The timing, however, is more complicated than that. For example, some of
Henkin’s most important foreign relations law work dates to well before his 1972 book
and includes a number of articles from the 1950s and 1960s,29 as well as a 1958 book
that, despite its narrower focus, was in many ways a precursor to his 1972 book.30

25
See LOUIS HENKIN, FOREIGN AFFAIRS AND THE CONSTITUTION (1972).
26
The casebook, with new authors, is currently in its Fourth Edition. See THOMAS FRANCK,
MICHAEL GLENNON, SEAN MURPHY, AND EDWARD SWAINE, FOREIGN RELATIONS AND NATIONAL
SECURITY LAW: CASES, MATERIALS, AND SIMULATIONS (4th ed. 2011).
27
The casebook is now in its Sixth Edition. See CURTIS A. BRADLEY & JACK L. GOLDSMITH,
FOREIGN RELATIONS LAW: CASES AND MATERIALS (6th ed. 2017).
28
See, e.g., HAROLD HONGJU KOH, THE NATIONAL SECURITY CONSTITUTION: SHARING POWER
AFTER THE IRAN-CONTRA AFFAIR (1990); MICHAEL J. GLENNON, CONSTITUTIONAL DIPLOMACY (1991);
THOMAS M. FRANCK, POLITICAL QUESTIONS/JUDICIAL ANSWERS: DOES THE RULE OF LAW APPLY TO
FOREIGN AFFAIRS? (1992); MICHAEL D. RAMSEY, THE CONSTITUTION’S TEXT IN FOREIGN AFFAIRS (2007).
29
See, e.g., Louis Henkin, The Treaty Makers and the Law Makers: The Niagara Reservation, 56
COLUM. L. REV. 1151 (1956); Louis Henkin, The Foreign Affairs Power of the Federal Courts: Sabbatino,
64 COLUM. L. REV. 805 (1964).
30
See LOUIS HENKIN, ARMS CONTROL AND INSPECTION IN AMERICAN LAW (1958). In the
Introduction to this book, Henkin described it as “essentially a memorandum of law, an examination of
problems which arms control and inspection may raise under the Constitution and laws of the United
States.” Id. at 3. But the study was wide-ranging and included, for example, a consideration of legal issues
that might be entailed for the United States of joining an international criminal court. In his 1972 book,
 9

Moreover, in 1965, the American Law Institute published the Restatement (Second) of the
Foreign Relations Law of the United States,31 the work on which began in the mid-
1950s.32 Restatements are non-binding but influential efforts by groups of legal experts
that describe the state of the law in a particular field. The first Restatement of Foreign
Relations Law was labeled the Restatement (Second) because it was part of the second
series of Restatements published by the American Law Institute. A more expansive
Restatement (Third) was published (in two volumes) in 1987, and Henkin was its Chief
Reporter.33 In 2012, a Restatement (Fourth) project was initiated, and materials on
treaties, jurisdiction, and immunity have now been completed; several of the Reporters
for that project are authors in this volume. The key point for present purposes is that
foreign relations law has been conceived of as a field within the United States at least
since the initial development of the Restatement (Second) in the 1950s.

But the field of foreign relations law in the United States also predates the
Restatement projects. As Henkin made clear in the Preface to his 1972 book, he was
writing against the backdrop of earlier generations of work from the late nineteenth and
early twentieth centuries, and he noted that he was “much indebted” to Quincy Wright’s
book, The Control of American Foreign Relations, which was published in 1922.34

Henkin also made several perceptive suggestions about why there had been a long
gap in scholarly attention to U.S. foreign relations law, and some of these suggestions
may be relevant to why foreign relations law has been less developed as a field outside
the United States. First, he observed that the field of constitutional law in the United
States had become heavily focused on Supreme Court decisionmaking, and that the Court
was not frequently engaging with foreign affairs cases during the post-World War II
period.35 Second, he speculated that as both constitutional law and international law had
expanded as part of the general growth of public law, they may have “developed into
separate expertise of different experts.”36 Finally, he suggested that foreign relations law
“fell between the constitutional lawyer and the international lawyer, perhaps nearer to the
latter, but his credentials in constitutional law were not universally accepted and he was
himself less than wholly comfortable with its matter and manner.”37

Henkin noted that he was drawing on his earlier writings, including the 1958 book. See HENKIN, supra
note 25, at x.
31
RESTATEMENT (SECOND) OF THE FOREIGN RELATIONS LAW OF THE UNITED STATES (1965).
32
As the Introduction to the Restatement (Second) notes, the work on it “was made possible by a
grant from the Ford Foundation awarded in 1955, after a preliminary study financed by the Rockefeller
Foundation.” Id. at vii. For additional discussion of the genesis of the Restatement (Second), see DAVID
L. SLOSS, THE DEATH OF TREATY SUPREMACY 271-80 (2016).
33
Unlike the focus of this Handbook, the Restatement (Second) and the Restatement (Third)
defined foreign relations law to include international law, although their coverage of the international law
applicable to the United States was very selective.
34
See QUINCY WRIGHT, THE CONTROL OF AMERICAN FOREIGN RELATIONS (1922).
35
HENKIN, supra note 25, at vii-viii.
36
Id. at viii.
37
Id.
 10

During the pre-World War II period that Henkin saw as an earlier time of
vibrancy in foreign relations law, the United States was emerging as a major world
power. Not coincidentally, the presidency was also becoming a more robust institution,
including in foreign affairs. In addition, there were efforts in this period to increase the
scope and effectiveness of international law and institutions—through, for example,
expansions of inter-state arbitration. These developments generated intense discussions
within the United States about the limits of presidential authority, the extent to which the
government could conclude international agreements without obtaining the advice and
consent of a supermajority of the Senate, the relevance of federalism to the government’s
foreign affairs powers, the constitutionality of delegating U.S. “sovereignty” to
international institutions, and the proper role of the courts in evaluating the government’s
foreign affairs decisions and actions.38 There was particular reflection on these issues in
the wake of World War I and the Senate’s rejection of the Versailles Treaty, and Quincy
Wright’s book was written against the backdrop of these events.39

By the end of World War II, by contrast, the central debates in foreign relations
law had been at least temporarily resolved.40 The debate between nationalism and
federalism had been resolved in favor of nationalism. The debate over executive power
had been resolved in favor of the President. The Senate’s role in the treaty process was
weakened. Courts largely deferred to the political branches. These debates would later
reopen, of course—first after Vietnam,41 then after end of the Cold War, and then again
after 9/11. Exogenous shocks in international relations, in other words, have tended
periodically to revitalize the field of U.S. foreign relations law.

There has been an especially high level of contestation in the field of foreign
relations law in the United States during the past several decades, with various
“revisionist” challenges to orthodoxy.42 Some of these challenges have pressed for more
attention to structural constitutional considerations that may limit or filter the domestic
application of international law. The U.S. Supreme Court during this period has been

38
See, e.g., EDWARD S. CORWIN, THE PRESIDENT’S CONTROL OF FOREIGN RELATIONS (1917);
LOUIS L. JAFFEE, JUDICIAL ASPECTS OF FOREIGN RELATIONS (1933); HAROLD W. STOKE, THE FOREIGN
RELATIONS OF THE FEDERAL STATE (1931).
39
In the Preface to his book, Wright described the genesis of his thinking that ultimately led him
to write the book: “In the winter of 1920, with the Treaty of Versailles still unratified and unrejected by the
Senate,” he discussed with colleagues “a subject then in the front of everyone’s mind—the American
system or lack of system for controlling foreign relations.” WRIGHT, supra note 34, at ix.
40
See generally G. Edward White, The Transformation of the Constitutional Regime of Foreign
Relations, 85 VA. L. REV. 1 (1999).
41
Henkin’s treatise was self-consciously written “in the quicksands of Vietnam.” HENKIN, supra
note 25, at viii.
42
Professor Jack Goldsmith and I authored one of the initial challenges, concerning the domestic
status of customary international law. See Curtis A. Bradley and Jack L. Goldsmith, Customary
International Law as Federal Common Law: A Critique of the Modern Position, 110 HARV. L. REV. 815
(1997).
 11

receptive to some of this revisionist thinking.43 Whatever one’s views about these
critiques and the responses they have generated, this dialogue has helped to give vibrancy
to the field of foreign relations law in the United States. Scholars of U.S. foreign
relations law today (a number of whom are authors in this volume) vary significantly in
their ideological orientation, and the dialogue among them is generally perceived to have
strengthened the overall quality of the work in this area.

III. Foreign Affairs Exceptionalism

Early in my academic career, I coined the term “foreign affairs exceptionalism.”44

This term as I used it refers to “the view that the federal government’s foreign affairs
powers are subject to a different, and generally more relaxed, set of constitutional
restraints than those that govern its domestic powers.”45 This might mean, to take a few
examples, that the federalism constraints that apply to the government’s exercise of
domestic authority are weaker in the area of foreign affairs; that the usual separation of
powers understandings that apply in the domestic arena (such as the proposition that the
President is not a lawmaker) apply less strictly when foreign affairs are implicated; and
that the judicial role is more constrained in cases implicating foreign affairs than in cases
involving domestic affairs. Debates over whether and to what extent there should be
such foreign affairs exceptionalism have been a core part of scholarship relating to U.S.
foreign relations law.

Probably no Supreme Court decision reflects this concept of exceptionalism more

than United States v. Curtiss-Wright Export Corporation.46 This case concerned what is
known in U.S. law as the “non-delegation doctrine.” The idea is that Congress is not
allowed to transfer its legislative authority to the executive branch and thus, when it
grants authority to that branch, it must provide sufficient standards to guide the exercise
of that authority. The modern Supreme Court does not apply this doctrine vigorously and
allows even very broad delegations as long as there is an “intelligible principle” in the
legislation.47 But the Court was enforcing the doctrine more strictly during the 1930s
when Curtiss-Wright was decided, and the Court invalidated some domestic New Deal
legislation on that basis.

43
See Curtis A. Bradley, The Supreme Court as a Filter Between International Law and American
Constitutionalism, 104 CAL. L. REV. 1567 (2016).
44
See Curtis A. Bradley, A New American Foreign Affairs Law?, 70 U. COLO. L. REV. 1089, 1104-
07 (1999); Curtis A. Bradley, Breard, Our Dualist Constitution, and the Internationalist Conception, 51
STAN. L. REV. 529, 539 n.51, 555-56 (1999); Curtis A. Bradley, International Delegations, the Structural
Constitution, and Non-Self-Execution, 55 STAN. L. REV. 1557, 1582-86 (2003).
45
Bradley, A New American Foreign Affairs Law?, supra note 44, at 1096. For a slightly different
definition, see Ganesh Sitaraman & Ingrid Wuerth, The Normalization of Foreign Relations Law, 128
HARV. L. REV. 1899, 1900 (2015) (defining it as “the belief that legal issues arising from foreign relations
are functionally, doctrinally, and even methodologically distinct from those arising in domestic policy”).
46
299 U.S. 304 (1936).
47
See, e.g., Whitman v. Am. Trucking Assn’s, 531 U.S. 457, 472 (2001).
 12

At issue in Curtiss-Wright was legislation relating to the Chaco War between

Bolivia and Paraguay. Congress passed a statute providing that it would be a crime for
U.S. citizens and corporations to sell arms or munitions to either of the two countries in
the War if the President determined that a ban on such sales “may contribute to the
reestablishment of peace between those countries.” President Franklin Roosevelt
immediately made such a determination, and the executive branch subsequently sought to
prosecute the Curtiss-Wright Export Corporation and its officers for selling machine guns
to Bolivia. The defendants argued that the statute under which they were being
prosecuted was invalid because it delegated too much discretion to the President.

The Supreme Court explained that it was “unnecessary to determine” whether the
statute in this case would constitute an unlawful delegation of authority if it “had related
solely to internal affairs.”48 The Court then proceeded to describe the “fundamental”
differences between “the powers of the federal government in respect of foreign or
external affairs and those in respect of domestic or internal affairs.”49 Among other
things, it reasoned that, unlike its domestic powers, the federal government’s foreign
affairs powers “did not depend upon the affirmative grants of the Constitution” and
would in any event have “vested in the federal government as necessary concomitants of
nationality.”50 As a result, claimed the Court, “[t]he broad statement that the federal
government can exercise no powers except those specifically enumerated in the
Constitution, and such implied powers as are necessary and proper to carry into effect the
enumerated powers, is categorically true only in respect of our internal affairs.”51

The Court in Curtiss-Wright also emphasized the “very delicate, plenary and
exclusive power of the President as the sole organ of the federal government in the field
of international relations.”52 It noted that the President often has access to information
relating to foreign affairs that is not available to Congress. As a result, reasoned the
Court, it is often necessary for Congress to grant to the President “a degree of discretion
and freedom from statutory restriction which would not be admissible were domestic
affairs alone involved.”53

The author of the Court’s opinion in Curtiss-Wright was Justice George

Sutherland. Sutherland had been thinking about the distinction between foreign and
domestic affairs for many years prior to the decision. In 1909, when serving as a senator
from Utah, Sutherland wrote an essay entitled The Internal and External Powers of the

48
299 U.S. at 315.
49
Id.
50
Id. at 318.
51
Id. at 315-16.
52
Id. at 320.
53
Id.
 13

National Government.54 In this article, Sutherland sharply distinguished between the

constitutional law of domestic affairs and that of foreign affairs. About a decade later,
Sutherland delivered a series of lectures on this topic at Columbia Law School and
subsequently published a book based on them.55 Like his earlier article, and his later
opinion in Curtiss-Wright, the book takes the position that “[t]he rules of construction,
which apply when the government undertakes to deal with internal matters, may not
apply, in the case of external matters, in the same way, or to the same degree, or,
conceivably, in some cases, may not apply at all.”56 As one commentator observed,
Sutherland in Curtiss-Wright was “in the happy position of being able to give [his]
writings and speeches the status of law.”57

The analysis in Curtiss-Wright has been heavily criticized. Commentators have

especially resisted the idea that the foreign relations powers of the government are “extra-
constitutional,”58 and it seems unlikely that the Supreme Court today would endorse that
proposition. But the more general idea of foreign affairs exceptionalism—that is, the
idea that legal issues implicating foreign affairs are to be treated differently than legal
issues implicating domestic affairs—runs throughout much of U.S. foreign relations law.
One way that such exceptionalism has tended to manifest itself is through heightened
judicial deference to the executive branch in the foreign affairs area—on issues ranging
from treaty interpretation, to foreign official immunity, to predictions about likely
diplomatic consequences. Part of the justification for such heightened deference is
functional: that the executive branch has more expertise and access to relevant
information relating to foreign affairs than the other branches of government and that it is
desirable for the United States to speak with “one voice” in foreign affairs where
possible.

Some commentators contend that the U.S. Supreme Court has been shifting away
from foreign affairs exceptionalism since the end of the Cold War,59 although this claim
has been contested.60 The Supreme Court’s 2015 decision in Zivotofsky v. Kerry
suggests that the Court is still attentive to the comparative advantages of the presidency

54
191 N. AM. REV. 373 (1910). The essay was first printed as a Senate document in 1909. See S.
Doc. No. 61-417 (1909).
55
See GEORGE SUTHERLAND, CONSTITUTIONAL POWER AND WORLD AFFAIRS (1919).
56
Id. at 29.
57
David M. Levitan, The Foreign Relations Power: An Analysis of Mr. Justice Sutherland’s
Theory, 55 YALE L.J. 467, 476 (1946). For additional discussion of the decision, see, for example, Charles
A. Lofgren, United States v. Curtiss-Wright Export Corporation: An Historical Reassessment, 83 YALE L.J.
1 (1973), and H. Jefferson Powell, The Story of Curtiss-Wright Export Corporation, in PRESIDENTIAL
POWER STORIES 195 (Curtis A. Bradley & Christopher H. Schroeder eds., 2009).
58
See, e.g., Michael D. Ramsey, The Myth of Extraconstitutional Foreign Affairs Power, 42 WM.
& MARY L. REV. 379 (2000).
59
See Sitaraman & Wuerth, supra note 45.
60
See, e.g., Curtis A. Bradley, Foreign Relations Law and the Purported Shift Away from
“Exceptionalism,” 128 HARV. L. REV. F. 294 (2015); Carlos M. Vázquez, The Abiding Exceptionalism of
Foreign Relations Doctrine, 128 HARV. L. REV. F. 305 (2015).
 14

in the foreign affairs arena.61 In that case, the Court held that the President had the
exclusive authority to determine the U.S. position with respect to the status of Jerusalem
and that Congress had unconstitutionally interfered with that authority in attempting to
require the State Department to designate in the passports of U.S. citizen children born in
Jerusalem that the birthplace was “Israel.” While discounting some of the broad dicta
from Curtiss-Wright, the Court emphasized that the nation needs to speak with one voice
on the issue of recognizing foreign sovereigns and their territories and that “[b]etween the
two political branches, only the Executive has the characteristic of unity at all times.”62
The Court also explained that “[t]he President is capable, in ways Congress is not, of
engaging in the delicate and often secret diplomatic contacts that may lead to a decision
on recognition” and that he “is also better positioned to take the decisive, unequivocal
action necessary to recognize other states at international law.”63

Whatever one may think about foreign affairs exceptionalism, it should be kept in
mind that it does not mean isolationism or resistance to international law. Indeed, many
Supreme Court decisions that seem exceptionalist with respect to federalism or executive
power have made it easier for the national government to make and implement
international commitments and engage in international relations. For example:

Ÿ In Missouri v. Holland, the Supreme Court held that the national

government is not constrained by the federalism limits that apply to federal legislation
when it enters into and implements treaties.64 The Court made clear that it did “not mean
to imply that there are no qualifications to the treaty-making power,” but it said that “they
must be ascertained in a different way.”65 For the migratory bird protection treaty at issue
in that case, the Court explained that “[h]ere, a national interest of very nearly the first
magnitude is involved,” and “[i]t can be protected only by national action in concert with
that of another power.”66

Ÿ In United States v. Belmont, the Court (with Justice Sutherland

authoring the opinion) upheld President Roosevelt’s use of an executive agreement to
settle claims with the Soviet Union as part of his recognition of that government, and it
allowed such an agreement to displace otherwise applicable state law.67 Because of what
it described as the national government’s “complete power over international affairs,” the
Court reasoned that “all international compacts and agreements” are free from “any
curtailment or interference on the part of the several states.”68

61
See 135 S. Ct. 2076 (2015).
62
Id. at 2079.
63
Id. at 2086.
64
252 U.S. 416 (1920).
65
Id. at 433.
66
Id. at 435.
67
301 U.S. 324 (1937).
68
Id. at 331.
 15

Ÿ In Zschernig v. Miller, the Court held that an Oregon inheritance law was
invalid because, by in effect disallowing inheritance of Oregon property by heirs living in
Communist countries, it had the potential to “affect[] international relations in a
persistent and subtle way.”69 While acknowledging that the states have traditionally
regulated inheritance issues, the Court said that state laws in this area “must give way if
they impair the effective exercise of the Nation’s foreign policy.”70

Of course, exceptionalism might also cut in the other direction—for example, by

limiting the judicial role in a way that reduces enforcement of international law. Perhaps
that is how to view Banco Nacional de Cuba v. Sabbatino.71 In that case, the Court held
that, because of the danger of disrupting the executive branch’s management of foreign
relations, “the Judicial Branch will not examine the validity of a taking of property within
its own territory by a foreign sovereign government, extant and recognized by this
country at the time of suit, in the absence of a treaty or other unambiguous agreement
regarding controlling legal principles, even if the complaint alleges that the taking
violates customary international law.”72 In dissent, Justice White complained that the
Court had “with one broad stroke, declared the ascertainment and application of
international law beyond the competence of the courts of the United States in a large and
important category of cases.”73

Some degree of exceptionalism is probably inevitable, if for no other reason than

that the legal materials relating to foreign affairs sometimes have no precise analogue in
domestic law. For example, although treaties are similar in some ways to statutes in the
U.S. legal system, they are also different in that they are made through a different
process, and more importantly, they can create both international law and domestic U.S.
law and thus implicate issues of reciprocity not implicated by mere domestic legislation.
Similarly, although it is surely an overstatement to suggest that for the purposes of
foreign affairs the states “do not exist,”74 state actions relating to foreign affairs can create
externalities for the entire nation that need to be considered in evaluating the proper
application of federalism doctrines. And, while it is an overstatement to suggest that the
President is the only important actor for the United States in foreign affairs, the President
does possess unique access to information relating to foreign affairs and is able to act

69
389 U.S. 429, 440 (1968).
70
Id.
71
376 U.S. 398 (1964).
72
Id. at 428.
73
Id. at 439 (White, J., dissenting). The Supreme Court’s sovereign immunity decisions prior to
the enactment of 1976 Foreign Sovereign Immunities Act may be another example of how foreign affairs
exceptionalism will not necessarily promote compliance with or incorporation of international law. See,
e.g., Republic of Mexico v. Hoffman, 324 U.S. 30, 38 (1945) (“[I]t is the duty of the courts . . . not to
enlarge an immunity [of a foreign government] to an extent which the [U.S.] government, although often
asked, has not seen fit to recognize.”).
74
LOUIS HENKIN, FOREIGN AFFAIRS AND THE US CONSTITUTION 149-50 (2d ed. 1996).
 16

more quickly and in a more coordinated way in responding to foreign affairs

developments than Congress, which faces both collective action limitations and internal
partisan competition.

These observations are certainly not intended to suggest that the legal
understandings that apply to domestic affairs have no application to foreign affairs. In
many instances, these understandings very likely should apply—for example, with
respect to the protection of individual rights within the country. But part of the vibrancy
of the field of foreign relations law in the United States stems from the dialogue and
contestation over when foreign affairs genuinely merit different legal treatment.

IV. Conclusion

There is a certain amount of arbitrariness in any attempt to define a “field” of

legal study. When deciding whether to consider foreign relations law as a field, the
ultimate question is whether valuable insights can be obtained by focusing on its
particular collection of legal materials and doctrines.75 For U.S. scholars, the answer has
long been yes, and scholars in other countries are now increasingly finding that such a
focus can be useful.76 This book in turn asks another question: whether valuable insights
can be obtained by comparing these bodies of foreign relations law across national
jurisdictions, and with organizations like the European Union. The chapters that follow
explore that question, both generally and with respect to a variety of specific foreign
relations law topics.

As will become apparent in these chapters, common issues can be perceived when
studying foreign relations law across multiple jurisdictions. For example, a number of
countries have struggled with whether and to what extent their legislatures should
become more involved in foreign relations decisionmaking. On the one hand, executives
have certain advantages in foreign relations, such as a unitary voice, better access to
relevant information, and the ability to act quickly. On the other hand, foreign relations
decisions sometimes entail potential risks or tradeoffs for the nation that are sufficiently
serious that they might seem to warrant full democratic deliberation.

Another common issue concerns the proper role of the courts in foreign affairs.
Courts are likely to be sensitive to the danger that their interventions could undercut their
government’s effectiveness in foreign relations or create unnecessary friction with other
countries. But they may also perceive that the political process relating to foreign affairs

75
Cf. Todd S. Aagaard, Environmental Law as a Legal Field: An Inquiry in Legal Taxonomy, 95
CORNELL L. REV. 221, 242 (2010) (“At a minimum, a legal field must exhibit two characteristics:
commonality and distinctiveness.”); Lawrence Lessig, The Law of the Horse: What Cyberlaw Might
Teach, 113 HARV. L. REV. 501, 502 (1999) (“By working through these examples of law interacting with
cyberspace, we will throw into relief a set of general questions about law’s regulation outside of
cyberspace.”).
76
For potential tradeoffs associated with conceiving of foreign relations law as a field, see Karen
Knop, Foreign Relations Law: Comparison as Invention (draft chapter for this volume).
 17

is not by itself sufficient to ensure vindication of fundamental principles of either

domestic or international law.

Comparative foreign relations law overlaps with comparative constitutional law,

although it is broader in some respects and narrower in others. Foreign relations law
encompasses a wide range of public law materials, not just constitutional law, but it does
not extend to all of the issue areas that fall within the domain of constitutional law.
Moreover, the constitutional law relating to foreign relations law tends to be less
“judicialized” than other areas of constitutional law, and in part for that reason is often
given much less attention than domestic affairs in studies of comparative constitutional
law.77

As others have noted, doing comparative public law may be more challenging
than doing comparative private law, given the significant differences among countries in
institutional structures.78 Moreover, the public law of a country may be substantially
different in practice from what appears in its formal written law (that is true in the United
States, for example), making it difficult for outside observers to have an accurate sense of
it. Despite these challenges, there is a rich literature on not only comparative
constitutional law, but also comparative administrative law. That literature has become
analytically and methodologically sophisticated, and some of the concepts and
approaches developed in that literature may be of value when focusing on comparative
foreign relations law.79

77
Only one of the 64 chapters in the Oxford Handbook of Comparative Constitutional Law
directly concerns an issue of foreign relations law—the chapter by Yasuo Hasebe on war powers—
although some of the other chapters touch on the relationship between domestic law and international law.
Of the 33 chapters in Comparative Constitutional Law (Tom Ginsburg & Rosalind Dixon eds., 2011), only
two directly focus on foreign relations law, and on only one aspect of it—national security law. In his 1985
Hague lectures on comparative approaches to international law, W.E. Butler noted that comparative law
“has traditionally overlooked this realm” of comparative foreign relations law. 1 Receuil des Cours 83
(1986).
78
See Michel Rosenfeld & András Sajó, Introduction, in THE OXFORD HANDBOOK OF
COMPARATIVE CONSTITUTIONAL LAW 1, 2 (Michel Rosenfeld & András Sajó eds., 2012) (“Traditionally,
comparison in private law has been regarded as less problematic than in public law. Thus, where it seems
fair to assume that there ought to be great convergence among industrialized democracies over the uses and
functions of commercial contracts, that seems far from the case in constitutional law.”).
79
For a description of some of the approaches to comparative constitutional law, see Vicki
Jackson, Comparative Constitutional Law: Methodologies, in THE OXFORD HANDBOOK OF COMPARATIVE
CONSTITUTIONAL LAW, supra note 78, at 54-74.