If you join the military you should be prepared to be seperated many times over the course of the military career. There are a lot of programs set up on base for the wives (spouses) left behind. My DH was only over seas for 5 weeks (not Iraq) and I was give a page long list of things available for me including a pillow with a picture of my DH on it, a free oil change, free inhome daycare if I volunteered on base, free out of home day care (I think 5 hours a week?), and more that I can't remember. Also, when there is deployment to somewhere like Iraq there is a very strong since of unity in the spouses left behind. I got about 5 call from different authorites making sure my son and I were being taken care of.
However, I do think that war has an impact on marriages and there is probably going to be a rise during this time. Some rocky relationships just won't survive such a trying and stressful time. Not to mention the rate of cheating while the service member is overseas, because the spouse will never find out. Add onto that the fact that a marriage is rocky, and it just spells divorce. Out of 5 of my DHs closest friends ALL 5 have cheated on their wives at least once, if not multiple times. And most of these incidents were during 2 - 3 week TDYs inside the US.
So I have to agree with a pp who mentioned that if someone is going to cheat, they are going to cheat. Being in war time just sped up the process and gave them ample opportunity to do so.
Now, that ALL being said. I trust my DH 100%, he wouldn't cheat on me, I honestly don't think he has the balls to face me if he did something like that. Plus, he would be way too afraid of losing me and his children. My family is literally across the country and he would have a hard time visiting them. Plus, my DH didn't have sex with random woman before he was married compared to his friends who did. If he didn't do it before he was married I hardly expect it now.