MarineUS, you should revisit what prompted you to enlist, your answer is there.
You, and only you, can make this decision. I think you already know the answer anyway.
I agree 100%. When it comes to deployment orders, you go when you're ordered to go, pretty simple. When it comes to volunteering to go when you don't have to, the opinions of others shouldn't be the deciding factor even though getting the opinions of people you respect is a good idea. You know how you felt when you signed up, how you felt when you finished basic, and you probably have a good idea what your "mission in life" is, with regards to your military service. That ought to be enough to make your decision. And as RTR said, you probably already know what the answer is, even if it conflicts with your feelings in other areas like with how you feel about your fiance.
My specific suggestion is if you deploy, you really need to have your stuff in order back home, including uncomfortable issues like having the right paperwork for taking care of dependents and for taking care of yourself if you come home unable to care for yourself.
My other comments were focused entirely on the opinion aspects of the various suggestions, specifically Penguin's opinion being considered an extreme one. In my worthless opinion, Penguin's perspective is just a bit off of center and not extreme at all. It seems perfectly reasonable to me that someone who does not think that the war in Afghanistan serves the interests of the US would advise someone else to avoid voluntarily endangering themselves in what they see as a needless war. That isn't extreme, that's common sense. The mirror image of that opinion is the advice to actively volunteer to go to what some people think is a needless war simply because even if it isn't a war for national survival, our nation's leaders have made the call and a patriot will answer that call
every single time.
Again in my worthless opinion, those are opinions within the bounds of rational debate. The extremes are populated by people who advocate deploying just for the chance to kill some Muslims (yea those people exist), those who actually attack everyone in the military simply because they are part of an organization engaged in carrying out our national defense policy, and those who commit treason instead of participating in the legal processes to advocate policy change. Those are the extremes and in my opinion despicable positions, and I didn't see any of those opinions in messages here.
One of my Dad's best friends in high school went back to Vietnam 3 times as an airborne FAC and spotter, after serving his time his first deployment. He didn't make it back from his third trip, so I grew up understanding full well the implications of volunteering to return to a hotly debated war. And I have volunteered to participate in several hotly debated military activities in the last couple of years not because they would make me look good in front of my peers, and certainly not because they might help my career, but simply because I felt that participating in the process would be preferable to just complaining about what others are doing about some important issues. So trust me, I also know exactly what volunteering for an unpleasant and controversial mission is like.