Assuming you're in NA, I think your only options would be to run and hide somewhere, preferably with a bunch of like-minded people that you can rely on, or escaping to a neutral third country that won't repatriate your ass. If it comes to a hot war between NATO and Russia that somehow doesn't escalate to nukes I don't think bone spurs/shitting yourself/standard medical exemptions are going to apply, or at least they won't apply indefinitely. Being rich and powerful/being the child of the rich and powerful might help dodge conscription but I wouldn't want to rely on that.
Assuming you're in NA, I think your only options would be to run and hide somewhere, preferably with a bunch of like-minded people that you can rely on, or escaping to a neutral third country that won't repatriate your ass. If it comes to a hot war between NATO and Russia that somehow doesn't escalate to nukes I don't think bone spurs/shitting yourself/standard medical exemptions are going to apply, or at least they won't apply indefinitely. Being rich and powerful/being the child of the rich and powerful might help dodge conscription but I wouldn't want to rely on that.