Eiza González, Alex Pettyfer and Henry Golding also star in the semi-fictionalized account of a covert mission unofficially mandated by Churchill to neutralize Nazi U-boats in the North Atlantic.

With 2023’s compelling Jake Gyllenhaal vehicle The Covenant, Guy Ritchie took a more serious dramatic turn, away from the flashy action, glib humor and mashup of period settings with contemporary attitude that had characterized many of his biggest commercial successes. With its typically Ritchie-esque ensemble of quippy rascals, The Ministry of Ungentlemanly Warfare sees the director back on more customary territory. Sort of. Chronicling a covert World War II mission manned by a band of renegades, the movie is diverting but remains awkwardly stuck between a larkish caper and a more gripping combat action thriller.

The film follows the semi-fictionalized covert special forces mission manned by a maverick crew to neutralize the German U-boats that are pulverizing the Brits in the North Atlantic. Conceived with the approval of Churchill (Rory Kinnear) by a Naval Intelligence division that includes Brigadier Gubbins, code-named “M” (Cary Elwes), and a young Ian Fleming (Freddie Fox), the harbor raid is dubbed “Operation Postmaster.” But the plan is unauthorized, unsanctioned and unofficial, meaning the recruits risk imprisonment if discovered by British forces and death if captured by the Nazis.

The director at times seems to be going for the kind of swaggering irreverence Quentin Tarantino brought to World War II action in Inglourious Basterds. But Ritchie never quite nails the tone, even if his principal actors seem convinced they’re in a rollicking adventure. The movie bounces along briskly enough over a full two hours and is never dull, but it’s never terribly exciting, either, full of wisecracks that rarely crackle.

Chosen to lead the mission is Major Gus March-Phillipps, a high-born eccentric granted early release from a prison sentence. He’s played by Henry Cavill and a spectacular handlebar mustache. Gus insists on choosing his own team, starting with Anders Lassen (Alan Ritchson), “The Danish Hammer,” known for his skill with a bow and arrow, not to mention knives and, in one frenetic scene, an ax.

Next up come Irish sailor Henry Hayes (Hero Fiennes Tiffin), a navigational expert; Freddy “The Frogman” Alvarez (Henry Golding), a demolitions specialist whose underwater stamina makes him invaluable in planting explosives to sink ships; and master planner Geoffrey Appleyard (Alex Pettyfer). The latter requires a detour to break him out of a garrison in the Canary Islands, where he’s being held by the Nazis.

The Postmaster crew have help from Richard Heron (Babs Olusanmokun), a clandestine comms expert who runs a casino in the port as cover. And sharp-shooting actress Marjorie Stewart (Eiza González) is entrusted to seduce the hardass outpost commandant, Heinrich Luhr (Til Schweiger), keeping him busy at a casino costume party where she performs a vampy version of “Mack the Knife.”

Naturally, complications ensue once Phillipps and company are en route, but no obstacle ever proves especially daunting for the team. This means maneuvers that should be nail-biters look like a piece of cake for the jolly Postmaster crew, and despite a considerable number of explosions and gunfire exchanges, it all seems a bit too easy to ramp up the conflict or build suspense. Chris Benstead’s jazzy score only adds to the lightweight feel of it all.

The cast acquit themselves well enough, especially Ritchson, whose brawny character is happiest when wielding a deadly blade, though I can’t say I bought González as a 1940s femme fatale skilled in subterfuge. The character seems fanciful, even if Marjorie Stewart is one of the handful based on real people. The normally reliable Kinnear is a curiously ineffectual Churchill, especially coming after Gary Oldman and John Lithgow’s artful impersonations in The Darkest Hour and The Crown, respectively.