The Secret War of Harry Frigg

Several brigadier generals (American, British, and French) are unexpectedly taken prisoner by the Italians while arguing military tactics in a sauna - which is a public relations disaster. They are held in an Italian villa run as a top level prison camp by benevolent Italian Colonel Ferrucci. Being all of the same rank, none is in command and they are forced to plan escapes by committee, with predictably ineffective results.