Why Wait Four to Six Months in Iraq?

This week, Democratic Senator Carl Levin proposed that the U.S. begin withdrawing troops from Iraq in four to six months. Granted this is vastly superior to the Bush 'plan' which seems to be 'change absolutely nothing 'cuz it's worked damn well so far.' But I have a question: why wait four to six months?

I'm leaving town for Thanksgiving, and as always, I'm running around, trying to finish things up, and do all those stupid little things you have to do before you go away for a while. It seems to me that's what that four to six months is for. Unfortunately, I haven't heard what exactly that 'window' is for. There's no plan there. Instead, the plan seems to use a time figure that is politically acceptable--four to six months is less than "over half a year." We wouldn't want people to think that we want to withdraw now. They might think we're dirty, stinkin' hippies (will the stranglehold the babyboomers hold over the zeitgeist ever end...).

If we are not going to do any specific things in this 'window', then why don't we start withdrawing now? It's not clear what we can do in four to six months that we couldn't have done in three years, except click our heels even faster while wishing for more pretty ponies. Back when John Kerry was eloquent, he asked, "What do you say to the last man to die for a mistake?" If there's no concrete plan for the next four to six months, save our fellow citizens' lives and start withdrawing now.

Update: Atrios and AJ at AmericaBlog have more.