“Welcome to ‘Nam,” jokes a soldier knee-deep in rice-paddy muck early in this austere war doc, which tracks a NATO-attached Danish platoon’s six-month tour at the titular Afghanistan army base. It’s a fitting metaphor for the tech-enhanced death-tourism that passes for modern warfare on display in the film, and typical of the quietly mortifying ironies it exposes. While much of Armadillo echoes last year’s Restrepo, the unprecedented access of director Janus Metz and cameraman Lars Skree reveals the alternating waves of frontline tedium and terror with fresh immediacy. This is partly because their film is edited and scored like a feature, but its bullet-dodging p.o.v. narrative also immerses us in the war’s overall motivational vacuum and the dilettantish involvement of countries like Denmark. The notion of “adventure” comes up often, and there’s a horrifying sense that the platoon feels duly compensated after routing five Taliban fighters in a ditch; Metz has been criticized for taking no moral position, but this sequence says practically everything that needs to be said. As for that crack about Vietnam, the real punchline comes when a farmer shows the Danes a route around the bog. Is it too much to hope that somebody in charge was taking notes?