Apart from a ridiculous scene which was supposedly set in the desert (but the background is CLEARLY a cheap painting), "Foxhole in Cairo" is a terrific espionage flick set during WWII.
During the early portion of the battle for North Africa between the British and Germans/Italians, the British did not do very well. At one point, the British lost so many battles that they were left with a portion of Egypt...and that was it. This movie is set during this time and is about a German attempt to sneak spies into Cairo in order to report on the British troop movements. However, the Brits are pretty savvy and the film is about their efforts to find these spies pretending to be Allied soldiers.
The film has a slow, serious tone...and this might lose some viewers. But it you are patient and don't mind the tempo, the film rewards you with some excellent acting, taut action and a terrific finale. All in all, well worth seeing...and not just for this but to catch a glimpse of Michael Caine in one of his early, albeit small, roles.