GEN. McCHRYSTAL WROTE THAT 12 MONTHS IS THE CRUCIAL TIME FRAME

And Pres. Obama provided extra troops for 12 more months.

Obama's Afghanistan timeline adheres to McChrystal assessment
The Afghanistan timeline President Obama outlined Tuesday calls for the 'surge' of 30,000 new troops to abate after only 18 months. That time frame is consistent with what Gem. Stanley McChrystal has called the 'decisive' period of the war.

By Mark Sappenfield | Staff writer of The Christian Science Monitor
from the December 2, 2009 edition

President Obama's decision to set a timeline on the "surge" of 30,000 new US troops into Afghanistan is consistent with a vehement assertion from Gen. Stanley McChrystal, the top US commander in Afghanistan, in his battlefield assessment.

In urgent language, McChrystal stressed the importance of time in America's Afghan venture – suggesting that the next 12 months could well determine the success or failure of the mission.

The timeline Mr. Obama announced Tuesday night appears geared to providing McChrystal with as many boots on the ground in Afghanistan as soon as is logistically possible in an effort to turn the tide of the war.

The consistency between McChrystal's assertions and Obama's words Tuesday appears to provide a military rationale for the timeline, which has been criticized as a purely political ploy made with the 2012 elections in mind.