The reality of the situation is that the US does not have the troops to do what it's doing now, much less invade anyone else. The Marines haven't even been able to meet their recruitment quota in the last couple months, and the Guard and Reserves and really hurting. Keeping military personnel beyond their enlistment (what we used to call "the duration plus six") used to be used ONLY for VERY critical skills or during declared war; now it's standard practice.

Short of a draft -- and that would be political suicide and possible impeachement -- the US military is going to be squeaking along for some time. An invasion of anybody is out of the question right now.

But think of this:

North Korea pulls the trigger and atom bombs Seoul and Tokyo (and don't for a minute think that I'm being either a war or fear monger here -- them folks in charge in NK are nuts), and North Korean troops cross the DMZ en masse, a la 1950. What then? W is pulling US troops from South Korea to shore up the Iraq thing, and South Korea would have its hands more than full. And don't forget that Japan is going to be EXTREMELY annoyed.... And to add to the mix, what will China do?

Iran isn't on the table. In my view, North Korea is.