Tom Cruise shows off his 50something abs in ‘Mission: Impossible —

IN THE NEW "Mission: Impossible - Ghost Protocol," Tom Cruise and friends traverse the globe trying to recover stolen launch codes for Russian ICBMs.

It made me wonder: Are the Russians still running Windows 98? I ask because here at the Daily News, where we do not launch ICBMs, we have to change our passwords every other day, and re-enter it every time we leave the desk for two freaking minutes.

I mean, if someone stole your ICBM launch codes, wouldn't you . . . change them?

A more pertinent question is: Who really cares? The "Mission: Impossible" franchise is not John Le Carre, or even Tom Clancy. It's a blown-up TV show and its purpose is to provide Cruise a forum to perform amazing movie superstar stunts, this time in IMAX.

"Mission: Impossible" opens today in IMAX theaters only, and contains 30 minutes of footage photographed with IMAX cameras. The bulk of it appears to involve a stunt that has Cruise (and/or his body double) dangling from the world's tallest building in Dubai.

It's undeniably fun. Director Brad Bird takes his IMAX camera to one of the top floors, moves it toward an open window, then peers over the edge - the stomach-plunging effect is like being at the precipice of a roller-coaster peak.

Will it play the same way in standard theaters, where the movie widens next week? Probably not, but that is why Cruise takes off his shirt so much. Cruise is now in the Men's Health phase of his career, immensely proud of his middle-aged abdominals and rib cage, eager to show them off. Watching "M: I," we know there is a long-term future for Taylor Lautner.

Shirtless Tom evades an army of Badanovs at the Kremlin, hustles to Dubai to do Spider-Man stuff on the skyscraper, then it's off to Mumbai. No matter where he goes, there seems to be a BMW handy.

All of this seems designed to prove that Cruise, at 50, can still do more push-ups than Jason Bourne. Well, the jury's still out. Cruise looks fit, and the over-the-top action is amusing, but it takes him an awfully long time to beat the crap out of the movie's villain, who's like, 60 years old, 30 pounds overweight and wears a pinkie ring. I was not impressed.

Some of the pugilism has been off-loaded to new co-star Jeremy Renner, and Paula Patton has a nice fox-fight with a hit woman (Lea Seydoux).

Simon Pegg, as the technician, provides the laughs, and has a great scene with Cruise in which they mask a data-theft operation with a gossamer screen that projects the image of an empty hallway. It's a very clever sequence, and director Bird comes up with some funny visual riffs.

"M: I" has a James Bond-like fetish for technology, and makes repeated use of a contact lens computer that scans crowds for dangerous individuals, then rings your cellphone if it spots one.

Too late for one agent. Before his phone rings, he's gunned down in a desolate back alley by a gorgeous woman wearing a trench coat.

The guy needs an eyeball computer to tell him she's trouble? I guess he never saw "The Sting."