Buried in the unfortunate rhetoric of timelines and exit strategies is a critical fact that gives reason to support the ongoing effort in Afghanistan: The president intends to give Gen. Stanley McChrystal 100,000 U.S. troops to use at his discretion for 18 months to pursue a counterinsurgency strategy. McChrystal and his team are the most clear-eyed and determined command group the United States has had in Afghanistan in years. They feel the urgency of the mission. They understand the enemy, the people, the terrain and the challenges of the government with which they must work. And they know how to fight counterinsurgency.

There are causes for concern in the president's remarks: the unconditional start of a transition to Afghan responsibility in July 2011; the refusal to set an appropriately high target for the size of Afghan security forces; and the provision of fewer U.S. troops than McChrystal originally requested. Nevertheless, the task of securing Afghanistan is critical, and with the extra forces there is a reasonable prospect of success.

Frederick W. Kagan is the director of the critical threats project at AEI. Kimberly Kagan is president of the Institute for the Study of War.