Odds of a military draft

To start with, there would have to be something really major to happen before they would bring back the draft. And yes, to start with, they would have to do it the way it is set up by current Selective Sevirce law and begin with a lottery for those between the ages of 18-25. Those who would want to volunteer to join would also be taken in up to age 39, especially if you've had prior military service and the MOS you have is something that they require at the moment, like infantry, tanker, airmen, intelligence, etc.

Maybe you should grow a big ole set of testicles and join without being drafted.