NEW DELHI — America's war in Afghanistan is approaching a tipping point, with doubts about President Barack Obama's strategy rising. Yet, after dispatching 21,000 additional U.S. forces to Afghanistan, Obama is considering sending another 14,000 combat troops there. Let's be clear: America's Afghan war is just not winnable.

First, Obama has redefined U.S. goals too narrowly. America's primary goal now is not to defeat the Taliban but to prevent al-Qaida from using Afghanistan as a base to launch an attack on the United States.

Obama told the Associated Press in a July 2 interview, "I have a very narrow definition of success when it comes to our national security interests, and that is that al-Qaida and its affiliates cannot set up safe havens from which to attack America."