This is a 1940 spy thriller directed by Alfred Hitchcock.
An American reporter tries to expose enemy spies in Britain who are involved a fictional continent-wide conspiracy in the prelude to World War II.
Apparently, it is a British-American propaganda.
The plot is unskilfully contrived, but the timing of its release was pretty good because the film opened on 16 August 1940 in the United States and on 11 October of that year in the United Kingdom.
The storyline ends with London being bombed just three days after the Luftwaffe began bombing British coastal airfields in the early Adlerangriff phase of the Battle of Britain, and a week before Germany actually began bombing London.
Although it seems like an unnecessarily-and-tiringly long glorified B movie, Nazi Propaganda Minister Joseph Goebbels praised it as a first-class propaganda film.