Alright, I'll give you my thoughts
first you need to know that I come from a Family with a decent history with the armed forces (5 uncles, both grandfathers) but no one in my generation yet, and I also have a lot of friends in the armed forces, some getting ready to go over to the sandbox right now.
This is what I'm going to say, first of do not base your decision on the War in Iraqi, Honestly it pisses me off all these people who say , "well don't join because think the war in Iraqi is wrong", congratulations, pat yourself on the back, you just fall in with a lot of other people who currently can not comprehend the fact that wars come and go and todays Iraqi might be tomorrow's Darfur. I'm not going to get into a debate on the war I'm just trying to tell you to not make your diccision to join by what is currently happening.
Second, If you feel strong enough about it, your mom should understand that and support your decision.
Third, I have a question for you, What is making you want to join so bad? What is the reason you want to sign your life to the government, and what branch are you looking into?
The main problem is that people don't fully understand what the armed forces is all about, they can take so many people becuase they break you down and rebuild you from square one to be someone else. You always here parents saying that their kids change when they go off to boot camp, well it's true, they do, and usualy they change for the better.
Finally, I forget if your were going to do direct enlist but if you want to get your education before you go, look into ROTC, you can go through college, get your degree, and then you spend your years with the armed forces.
Whatever your decision - it has to be yours and from your heart and head. Don't let other sway what you truly want to do, the military is not an easy thing to do and it is not an easy thing to comprehend unless you have either experienced it or have family members who can tell relate these things to you (although you still will not fully understand them) I personally know that I do not fully understand it and that the only way I can fully understand it is to sign up and go find out for myself.
Yeah, it was long, but if you read it, I think that it might help you.