So what's the goal?

Watching (well, listening) to the debate on the Murtha Amendment in the House and reading that the Pentagon is actually planning for troop withdrawals in Iraq has me wondering it Republicans aren't backing themselves into a corner.

They keep saying we need to win, see this through to victory, etc. While it sounds good to the ears, doesn't that mean they will need a specific and rather large event that would mean the end of the war? Even the capture or death of Zarquawi wouldn't count, because obviously we did not invade Iraq to deal with him, but "terrorism" in general.

As Bush conceded in the election, there's no real way to win the war on terror. And, understanding that, there is no real endgame in Iraq, either. So what happens then when nothing happens and Republicans suddenly decide that it's time? While Democrats may take a slight hit on the war now, it seems Republicans are being set up for a much larger fall down the road.

Listening to the GOP, their side of the debate is how wrong this resolution is for the troops and how anti-American it is. If that's really the case, then why did they bring this version up for a vote in the first place. Why don't Democrats ask that question on the floor?
*UPDATE* From The Corner:

BACKFIRE IN THE AIR [Kathryn Jean Lopez]
I have a very bad feeling about this GOP vote-force tonight. Listening to the emotional debate on the floor now...well, there was just some screaming, to give you an idea. Prediction: Dems vote no on a Republican resolution for immediate withdrawal. Dems easily frame the whole exercise as Republicans caricaturing sensible concerns about Iraq--and more specifically a mocking of Vietnam vet Marine Jack Murtha (witness John Kerry below).

Wow. Never thought I'd agree with Kathryn Jean Lopez.

Note the debate on the floor. Republicans are arguing that the bill should be voted down. Democrats, however, aren't arguing for the passage of the bill, but rather arguing this bill cuts off debate on the policies that led us into and currently lead us in Iraq.

If Republicans really feel that they can win that debate, why are they so afraid to engage in it?

The answer, I think, is they don't think they can.