In 2004 he wrote:
is likely, therefore, that a significant American military presence in Iraq will be necessary for some time.
So the question becomes how much pain can the Army stand before breaking? There is no obvious answer, for America has never tried to sustain its armed forces for so long without dramatically increasing their number. And the armed forces have been holding up amazingly well. But, eventually, the toll of separation from families for more than a year at a time, of back-to-back rotations that make the separation even longer, and of seemingly endless duty at the front lines of a complicated and dangerous insurgency, will likely damage the Army's morale.
With no relief in sight and a force too small for the current mission, the probability that the Army will break under the pressure increases day by day. Rumsfeld's callous and flippant responses to serious questions raised by troops in Iraq could bring that day ever closer. If it arrives, skilled and experienced officers and senior NCOs will begin to leave the force. Recruiting for the active force will go down. The National Guard and Reserve will wilt under the strain. The result will be a serious erosion of American combat power at a critical time, and the consequences could last for decades.
Kagan's been consistent on his basic desire to expand our military, to increase deployment in Iraq, and generally lengthen our commitment there. He's been less than consistent with his arguments to get us there, and very wrong with his predictions.
I liked this one from 2005:
The Bush administration is making it clearer day by day that it intends to withdraw American troops from Iraq rapidly and roughly in step with the increase in the number of Iraqi troops deemed capable of taking over security responsibilities. Even while denying rumors of a rapid withdrawal of U.S. forces, President Bush has declared that "as Iraqis stand up, we will stand down."