Perhaps there is a reason that America (and other nuclear powers, but America most recently) doesn't just nuke its enemies. If the enemy group were truly a barbarian horde, with no sympathy generated from the remainder of the world, then perhaps rationalists would find it easier to nuke them. But in any other circumstance (which is to say, the Least Convenient Possible World), the things you described above would be useful (amnesty etc.). We only nuke 'em when that produces the best long-term outcome, including the repercussions of the use itself--such as the willingness of other countries to use such weapons for less defensive purposes.

The draft is objectionable not because it selects for the best soldiers but because it is overused, if I read the original post correctly. Proper use of the lottery/draft is only for directly defending the security of the original state, rather than projecting the whims of kings onto the world.