There’s lots of potential for “This Means War” to be a great time at the theaters. Director McG knows his way around a fluffy, paper-thin storyline, having cut his teeth on the short-lived “Charlie’s Angels” franchise, and Chris Pine and Tom Hardy are both interesting, likeable rising stars. Add in the film’s intriguing spy vs. spy premise and “This Means War” could have been the rare enjoyable Valentine’s Day movie, one that guys can take their dates to and come out with all brain cells intact. Unfortunately, all of those ingredients come out to make a half-baked, badly written film that’s about as memorable as the soda you’ll drink while watching it.

We’re introduced to agents Tuck (Tom Hardy) and FDR (Chris Pine) in a slick opening sequence in which the two charm women, wear suits and fight bad guys. All appears to be well with their rock-solid friendship. Then they both fall for Lauren (Reese Witherspoon) and, after deciding to let her choose between them and setting a few ground rules for their competition, immediately begin undermining each other in their quest for romantic supremacy.

For most of its runtime, “This Means War” is an easygoing, entertaining distraction. Its central friendship doesn’t feel forced; Pine and Hardy have a lived-in, quick-witted rapport that proves a solid foundation to build a film on.

Unfortunately, as things become increasingly sour between the two, the film begins to rely on their chemistry with Witherspoon. While she plays well with others and none of her scenes are painful, Witherspoon’s character is too inconsistent to invest in, fluctuating between a romantically conflicted sympathetic figure and an emotionally manipulative witch a bit too frequently.

McG also performs fairly admirably. He keeps the film moving at a fast clip and stages plenty of stylish action scenes. He also packs the soundtrack with classic rock and even slips in a fun “Goodfellas” homage. Even if McG occasionally stumbles with a spastic, conspicuous editing style, his earnestness and enthusiasm for the project shine through.

Many of the problems in “This Means War” can be traced back to its screenplay, which, with a few more drafts and some plot twists, could have built on its intriguing premise to make a much better film. Unfortunately, writers Timothy Dowling and Simon Kinberg created a film in which almost every plot beat for the rest of the film is predictable from the first 20 minutes. Is it possible that the baddie (Til Schweiger), Tuck and FDR fight in the opening sequence and will return for revenge? Once Tuck and FDR make rules concerning their relationship with Lauren, is there any chance they’ll break them all immediately?

Even though it’s clear where the film is going, the ending has a much more significant problem. As the romantic conflict reaches a climax, “This Means War” becomes shockingly mean-spirited and cruel to its characters and then casts all the potential conflict stemming from the terrible things they’re doing to each other aside, having them reconcile all too easily. It’s disrespectful to the characters, to the film’s commitment to its premise and to the audience. And it leaves the film on a nasty, bitter note.

“This Means War” is by no means a terrible film and a pretty ideal release for Valentine’s Day. It’ll make boatloads of money from the romantically inclined but will quickly fade from all of their collective memories before winding up a forgotten film in the $5 DVD bin at Wal-Mart. While that’s the destiny for many lackluster films, it’s a shame that this one has to join the ranks because with that cast, that concept and that director, it really could have been something special.

Printed on, Tuesday February 14, 2012 as: Spy film falls short of potential