Replete with a certain kind of self-importance and self-forgiveness, this Afghan war movie starring Mark Wahlberg has a distinctively martyred America-at-bay feel. Rather like Ridley Scott's Black Hawk Down from 2001, it balances indomitable fraternal loyalty against strategic disaster and tacitly claims a net gain. The film is a pumped-up Hollywoodisation of a true story recounted in the 2007 non-fiction bestseller of the same name, about an ill-fated US Navy Seal mission to take out a leading Taliban commander in remote and mountainous north-eastern Afghanistan. In treacherous terrain, with inadequate air cover and patchy communication links, the four-man team was detected and hopelessly outnumbered, but battled on with extraordinary determination. Like the book, the film emphasises that their predicament was all down to a humane refusal to kill a gaggle of shepherds they initially stumbled upon; they let them go and later assumed, with some reason, that these civilians ran to the Taliban and raised the alarm. The Navy Seals were, it seems, just too soft-hearted. The action sequences are often good, though repeated and extended scenes of the team falling down hillsides are weirdly similar to the Andy Samberg comedy Hot Rod, and the music from Steve Jablonsky and the Texan band Explosions in the Sky is unbearably clamorous and coercive, finishing with a clunkingly misjudged use of a cover version of David Bowie's Heroes. It would be better to get a documentary about this episode, not a flag-waving drama.