Have you seen this image
We will, for now, assume that the photo is of an actual factual enlisted Navy man, and that it isn't a staged propaganda photo.
I appreciate that you don't want to fight in Syria. I don't want you to have to fight there either. But as long as you wear that uniform you don't get to pick and choose which battles you will fight. As long as you are a member of the United States armed forces you will have to salute, say "yes sir!" and do as you're told.
You don't get to say "I didn't join the Navy to fight...." of course you did. That's why the Navy (and all the branches of the military) exist - to fight. And while you wear the Navy uniform you will be compelled to fight.
If you really don't want to fight in Syria (or anywhere else for that matter) put down the sign and take off the uniform. Resign from the military.