"State Department" is a strange film because it's about politics in China but never mentions the communists--who assumed power the same year this film debuted! It's also a rather cheap and insignificant film.
The movie begins with a prologue about various workers in the foreign service who have given their lives for their country. One of these people is the subject of this film. Ken (William Lundigan) is the new vice-consul of a remote consulate in northern China. However, he just arrives at his new posting when a local warlord arrives and begins menacing everyone. This sort of stuff did happen in the 1920s and 30--and I assume that this is the time period in which the movie is based.
The film is decent but a bit dull. While it's not a bad film, it never rises to anything more than just barely average. Lundigan and the rest are pretty good--it's just that the story never seems too interesting.