If a big, dumb action movie knows it's a big, dumb action movie and revels in that fact, is that preferable to a big, dumb action movie making the mistake of thinking it's significant, relevant art?

That's the question to ponder — if you can think straight and your ears aren't ringing too badly — during "G.I. Joe: Retaliation." This sequel of sorts to the 2009 blockbuster "G.I. Joe: The Rise of the Cobra" seems to have some cheeky fun with itself, from Bruce Willis cheerily revealing the arsenal he's hiding in his quiet suburban home to RZA from the Wu-Tang Clan essentially showing up and playing himself. A major city is obliterated with the touch of a button and several others are in peril as the world hinges on nuclear destruction in what amounts to a hammy game of chicken.

Nothing matters really. This is a movie based on a Hasbro toy, after all — it's all spectacle and bombast. But at least "G.I. Joe" is aware of its vapidity compared to, say, last week's "Olympus Has Fallen," in which North Korean terrorists took over the White House in self-serious fashion but our secret-service-agent hero found time to make wedged-in, smart-alecky quips on the way to saving the day.

That's not to say that this "G.I. Joe" is good, aside from a couple of dazzling action set pieces, but at least it's efficient in its muscular mindlessness.

The elite military team of Joes, now led by Duke (Channing Tatum, returning from the first film), is sent to Pakistan to recover some nuclear weapons. But they find themselves double-crossed by their own government, led by an imposter president, and lose many among their ranks in a massive ambush. The survivors — Roadblock (Dwayne Johnson, reliable as ever), Flint (D.J. Cotrona, who's given no personality) and Lady Jaye (Adrianne Palicki, in full makeup for covert ops) — must find out who's running the country and get to the bottom of this villain's dastardly plan.

Turns out it's master of disguise Zartan, part of the enemy group Cobra, who's posing as the president while the real commander in chief is locked up in a bomb shelter. (Jonathan Pryce plays both roles; he's far too qualified for even one of them.) The three Joes realize they need help to bring him down, so they round up the far-flung Snake Eyes (Ray Park), the petite warrior Jinx (Elodie Yung, whose character trains with the Blind Master, RZA) and the reluctant Storm Shadow (Korean superstar Byung-hun Lee, an athletic and elegant specimen).

They also need some firepower, so they track down Willis' Original Joe, Gen. Colton, who provides his own personal gun show. (You'd never know there's a gun control debate in this country from watching this movie; it's all very macho and rah-rah. The flip side is, none of the casualties from all this sophisticated weaponry results in any blood. This is an astonishingly violent PG-13 movie.)

"Retaliation" initially was scheduled to come out last summer, but the studio pulled it and delayed its release to convert the movie to 3-D. With a director like Jon M. Chu, who's shown a flair for integrating 3-D with the dance extravaganza "Step Up 3D" and the concert film "Justin Bieber: Never Say Never," why not just shoot it that way in the first place? As it stands now, the extra dimension doesn't add much, and often is used in that simplistic, tried-and-true way of flinging things at us from the screen: bullets, throwing stars, etc.

There is one absolutely astounding extended sequence about halfway through, in which two teams of ninjas face off in a battle on the sheer cliff faces of the Himalayas. Using cables and zip lines, it's as if they're running, leaping and practically dancing on walls in the sky — a breathtaking piece of choreography in its own right, regardless of the dimension through which it's viewed.

"G.I. Joe Retaliation," a Paramount Pictures release, is rated PG-13 for intense sequences of combat violence and martial arts action throughout, and for brief sensuality. Running time: 110 minutes. Two stars out of four.

Motion Picture Association of America rating definition for PG-13: Parents strongly cautioned. Some material may be inappropriate for children under 13.