Should governments have the right to draft?

http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=153385

We’re discussing the possibility of re-instituting the draft in the U.S. in this thread. I’m wondering: under what circumstances is a draft moral? Are citizens obliged to risk their lives, or even just take a job they don’t want, because the government tells them to? Is the government justified in offering Heinleinian incentives to get people to join up? Is the government justified in requiring welfare recipients to join the military after x years/dollars are spent?

i’m of the opinion, however i can’t justify it, that a draft is only warranted when the homeland is under direct attack. A draft is never warranted to fight a war overseas.