So, maybe this opinion will change after I think over the movie more, but here goes first reaction:

Jarhead is an incredibly conflicted movie. It is very clear that the movie was trying to "say" something, but what that something was is where I am at a loss. Sure, a theme that ran through the film regarding war as something that damages people in some way. And, I would try my damndest to pull from the film anti-war themes, and call it a night. However, the mood that ran through this film shifted drastically from scene to scene, and produced, for me, an unease that I am not entirely sure was intentional.

Consider one of the earlier scenes in which the young marines are pumping themselves up with a screening of Apacalypse Now. The men are screaming at the screen, cheering wildly as sparks fly and gunners unload. Some men seem to have the movie memorized word for word. For my money, Mendes was trying to evoke a feeling of unease in this scene, but I couldn't help noticing many of the people in our theatre seemed to be enjoying the scene in a surprising way. This became a pattern. A scene would have me squirming in my seat, or absolutely appalled at the behavior happening onscreen and 3 rows behind me, two young men would be laughing and having a great time. The point I am driving at is that Jarhead is a very dangerous movie in the way that it is presented. Sure, I can view these scenes as a critique on frightening behavior in times of war, or in the military in general -- but someone else could walk out of the film feeling pumped up by the rock oriented soundtrack, the macho bullying, and the "lets kill some arabs" speech given chillingly by Chris Cooper. Jarhead walks a fine and confusing line.

Furthermore, I found Jake Gyhaldkjf;oazhjdfohspdoifpaj's character to be very frustrating. Clearly, he is the film's protagonist. However, in plenty of scenes I found myself appalled by his behavior, and not in a "how-terrible-look-at-what-extremes-he-has-been-driven-to" sort of way. When he expresses anger and disppointment at not being able to personally kill a "target" because the job was going to be done by someone else, am I supposed to wish he got the shot? He never gets to kill anyone because the war ends too soon. Am I supposed to feel sorry for him? Sure, I understand the point to whatever degree that these soldiers were put through this training and stuck out in the desert in poor conditions to just be sent back home again. That is terribly frustrating and upsetting. But, the way this idea is presented in Jarhead makes me think that we as an audience are supposed to feel bad that they didn't get to fight as opposed to being angered that they were put in the situation in the first place.

Finally, I was annoyed that some of the storyline seemed rather forced (Jake GyHDSJ's relationship with his distant girlfriend, for one).

As just a movie, there were plenty of things that I really enjoyed. There were scenes that had me absolutely riveted. Sam Mendes clearly knows how to compose a great movie scene. The film is beautifully shot, and technically impressive. And most worth the price of admission is an amazing performance by Peter Saarsgard. He steals every second of screentime, and makes 3 of the most memorable and intense scenes in the movie. His work in Jarhead solidified him, in my head, as the finest young character actor working in hollywood right now (the only other that seems to come close is Ryan Gosling).

So yeah. I wouldn't say "Don't see Jarhead." Despite its (somewhat glaring) flaws, there are a number of reasons to check it out. I am just warning you that you may find yourself a bit confused and a bit weirded out by the film's tone. I certainly was.