Amid all the hubbub about whether it's a good idea to set a date for when U.S. troops will begin leaving Afghanistan, it's probably useful to point out that the Bush surge in Iraq (also 30,000 troops) had an end point to it that everyone knew when it started -- and it was just 15 months.
The first "surge" troops of the Iraq era began arriving in February 2007, and continued arriving at the rate of one brigade a month for six months. The first "surge" troops to depart Iraq began leaving in April 2008 and were bascially out at an even faster pace. As Lt. Gen. Ray Odierno pointed out in this August 2007 briefing, "The surge, we all know, will end sometime in 2008, in the beginning of 2008. We know that the surge brigades will leave at 15 months, so that will be somewhere between April and August of '08 when those units will leave based on the 15-month rotation."
The same "they'll-just-wait-for-you-to-go" rhetoric was around then. But Iraq just marked its most peaceful month since the U.S. invasion -- with U.S. troops basically confined to their bases.
There's still a lot of debate about whether Iraq will hold together when American forces are finally gone in 2011. That's when we'll know if the surge really worked. And Afghanistan isn't Iraq. But right now experience doesn't suggest a deadline has made matters worse.