In the two years since the Afghan surge was announced, U.S. forces have systematically cleared out insurgent strongholds in the Taliban heartland. Afghan forces have grown in numbers and professionalism — showing admirable discipline and restraint after the recent Koran burning incident. About 90 percent of military operations are conducted jointly by Americans and Afghans. During the past 12 weeks, the number of enemy-initiated attacks has been 25 percent lower than a year ago.

The horrible murders allegedly committed by an American have not changed U.S. national interests: to stop the return of Taliban rule, to prevent the reestablishment of terrorist sanctuaries and to limit the destabilization of Pakistan. A great power that makes momentous decisions based on the deranged actions of a single soldier would cease to be a great power. It would be a historical joke.

And national security officials in the Obama administration are actively combating the idea that they are planning a hasty or chaotic retreat. At a recent round­table with reporters, senior officials made clear they have not been asked for drawdown options beyond the reductions that have already been announced. They dismissed reports to the contrary in the New York Times as unreliable. And they affirmed the need for a significant U.S. residual force in Afghanistan after the 2014 security turnover — both to conduct counterterrorism operations and to convince the Taliban that America can’t simply be outwaited.