Mr. Roberts, a historian, is the author most recently of "The Storm of War: A New History of the Second World War" (Harper, 2011).

James Bond, of all people, has turned metrosexual. "Skyfall," the 23rd movie in the genre—directed by Sam Mendes and opening in theaters Friday—has somehow turned the all-encompassing man's man into a kinder, gentler Bond.

There are still the casual killings and car chases, of course, but Bond has been shorn of that subtly menacing blend of sadism and political incorrectness that set him apart from Jason Bourne, Ethan Hunt and all the other identikit espionage heroes. By making Bond less personally dangerous, and even hinting at a bisexual past, the guardians of his brand are undermining precisely what has made that brand so special. This is all the more astonishing since the first 22 Bond films cost $1.55 billion to make but made $10.41 billion at the box office.

As a literary character in 12 novels by Ian Fleming, Bond first appeared during Winston Churchill's premiership. Now in his sixth silver-screen incarnation, played by Daniel Craig, he still has the capacity to thrill. But while mincing around in Tom Ford suits rather than Savile Row, with three buttons on his cuff rather than a gentleman's four, and drinking Heineken beer instead of martinis? Above all, can he long escape his upper-class background—schooling at Eton and Cambridge, service in the Royal Navy?...