MGM's "Crime Does Not Pay" series goes to war -- in this case, telling the story of the recruitment of a dissatisfied mariner and the elaborate -- and foiled -- plot to blow up a ship called "The Caramel" with chocolate.
By this point, the series had turned a bit stolid and neat in its execution, although it remained topical. The latter may not be an asset to the modern, casual audience. The dialogue is often spoken mechanically, but given that a movie like this could be a short B feature at another studio, the tendency to rush a bit can be forgiven.
Look for a very young Hugh Beaumont in a very brief bit as a chemist.