Can you beet the Draft?

I'm turning 20 this year and if we go to Iran, I'm afraid I'll be drafted.

I hear that if you don't step over this line on the induction ceremony, you're technically not a soldier yet and they cannot order you as a soldier yet.  So can you exploit this loophole to get out?

   I beat it during Nam. I was very active in the anti-war movement but my DOB came up #2 in the lottery. (I'd dropped one too many courses)
   I was ready for the guvmint though. I'd saved every cent working construction one Summer so I hired a shrink and said I was depressed but didn't know why.
   After a number of expensive visits he brought up the draft and suggested an attorney he knew. The Atty said big bureaucracies are easy to beat. (He was written about in Time magazine)
   About the 3rd physical a Major looked at my phonebook sized file next to the skinny ones of my BVD clad cohorts. The smart Major said; "You're not going are you?" I assured him there was no chance in hell. STAMP!!! 

1Y