While Terry-Thomas is not all that well-known today, he made some wonderfully funny films in the late 1950s and 60s. As for Peter Sellers, he made some ingenious and funny films. You'd think putting these two men together would result in a memorable film...but this is not the case with "Carlton-Brown of the F.O.". While mildly interesting, it's far from a classic. Given the material, it should have been a lot more interesting.
1959 was the same year that Peter Sellers starred in the wonderful parody of politics and a tiny fictional film, "The Mouse That Roared". Oddly, "Carlton-Browne" has a very similar plot, some of the same cast and came out at almost the same time! But, because "The Mouse That Roared" was such a wonderful film, "Carlton-Browne" has been forgotten.
The film is about the fictional country of Gaillardia--a tiny country that had been part of the British empire. When the film begins, the ancient British representative on the island alerts his superiors in the UK that "something is up" there. Apparently, some folks have been digging holes and some Russian-types have been seen there. This information eventually results in a series of international incidents that are all a microcosm of the struggle between the East and West at the time.
So why did the film turn out so ordinary? Well, most of it is the writing. It just isn't all that funny. And, what's worse is that Sellers is almost completely wasted. A very talented man, he DID have a habit of making brilliant and dull films throughout his career. While this one isn't bad, it is a bit dull here and there. Given a re-write, better pacing (it drags) and less "kooky" music, the film might have worked as a comedy. As is, it is a bit clever but that is all.