Peter Sellers and Terry-Thomas here vie for the honours in a dated but sparkling piece of bunkum. A comedy that aims at so many targets (the cold war US/USSR rivalry, the UN, the British civil service, 'banana republics'...) normally fails, but this certainly has more hits than misses.
There are two unmissable scenes. The first is a military march-past which is rolling-on-the-floor funny from first to last: the mixed up commentary (note the point when the commentator finally gets a sentence right!); the shenanigans on the parade ground; and the collapsing review stand all combine to excellent effect. Second, a more minor but tasty scene where a table dancer (she is dancing ON the table) distracts Terry-Thomas in the course of his diplomatic discussions- surprising how much eroticism can get through the ludicrously heavy censorship of the period!
John Le Mesurier does an effective job in a 'wicked uncle' role torn straight from the pages of 19th century melodrama. Those who recall him from his small role in Ben-Hur might have cause to reflect that here is a supporting actor who gets about a bit!
Overall, both Terry-Thomas and Peter Sellers have appeared in better films but, in parts, as funny a film as you are likely to find on a wet afternoon.