Unlikely stories can make great movies, or at least fun ones, and if this isn’t the former then it’s largely the latter.

It’s about a hard-partying US congressman (Tom Hanks) who suddenly becomes interested in the Soviet occupation of Afghanistan, so increases support for the rebels by calling in the many favours he’s collected.

Boasting a typically witty script from Aaron Sorkin, and a cast (including Philip Seymour Hoffman) capable of delivering it, it makes a potentially grim topic surprisingly entertaining — which is presumably why acknowledgement of the aftereffects is reduced to one subtle, but chilling, nod to 9/11.