In “The Ministry of Ungentlemanly Warfare,” British Prime Minister Winston Churchill authorizes an illicit mission to undermine Hitler’s fleet of German U-boats during World War II. The plan calls for renegades with little respect for the rules, led by a cocky ex-criminal named Gus March-Phillips (Henry Cavill), who’s released from prison and called into a top-secret briefing. Oblivious to etiquette, Gus pours himself a tall glass of Scotch, steals an entire box of cigars and struts over to the desk where a priggish-looking officer sits. Gus palms his lighter, making a fool of the uptight chap, who identifies himself as...