Afghan president Hamid Karzai's rejection of talks with the Taliban has, it seems, tossed water on the prospects of a “political solution” between Kabul and the insurgents. Karzai's decision, coupled with the recent statement of Admiral Mike Mullen about the Pakistani Inter-Services Intelligence's enabling of the Taliban, has created an opening and a need for a political success of another kind: a renewal, within the United States, of support for the ISAF effort in Afghanistan.

For Americans, the double rejection of the Taliban and their Pakistani sponsors should put in perspective the slim prospect of reaching some well crafted diplomatic solution—a “peace with honor”—in the war against the Taliban. It's also a reminder of the broader geopolitical context of the “war on terror.”

Mullen has it right: Reaching a secure Afghanistan is not just the product of disrupting and degrading the Taliban, it involves finding the right balance with Pakistan. This last order may be the tallest, not least because it involves a willingness to reconsider unsuccessful diplomatic practices.

With the pathway to a political agreement with the Taliban closed, victory in Afghanistan lies with leaving a viable government in Kabul. At the center of any effort to build an independent Afghan state is Hamid Karzai, who is much maligned for a realpolitik approach to statecraft, ties to corruption, and a changeable personality. But however correct these critiques may be, it is also true that Karzai is the product of a particular political system, a man with clear interests and largely predictable behavior and, crucially, whose political objects largely align with our own in the region.

The most important aspect of any lasting "political solution" is security. That remains foremost in the minds of Afghans—and also Iraqis. We cannot "kill our way to peace," but neither can we expect peace when our enemies would rather kill than talk. Americans do seem ready to talk—about what we should do in Afghanistan. The Republican primary has returned the war to a prominent place in the national debate, and has given an opportunity to candidates to voice their differences with the president on more than just domestic policy. The Republicans have a chance to offer a choice—win this war, don't just end it.

Thomas Donnelly is a resident fellow and director of Center for Defense Studies at AEI.

Richard Cleary is a research assistant at AEI.