How the US sustains corruption in Afghanistan in order combat the insecurity caused by people enraged by the corruption.

The meeting in a muggy tent at Kandahar Airfield was dragging on when a lieutenant colonel with the Army Corps of Engineers broke in with an uncomfortable question.

“I’m not sure how to put this,” he told some 40 American soldiers and civilians gathered here two weeks ago in the heart of Taliban territory. A commander of the Afghan border police had offered to give the U.S. military prime land at a crossing with Pakistan to build a waiting area for supply vehicles needed for President Obama’s troop increase. The same man, U.S. officials believe, earns tens of millions of dollars a year trafficking opium and extorting cargo trucks.

The lieutenant colonel wanted to know: “Does anyone else see this as a problem?”

The silence that followed revealed a basic dilemma the United States now faces in the war in Afghanistan. After eight years of dropping bombs and killing insurgents, the new American military strategy makes explicit the need to fight corruption to build a more legitimate Afghan government. But corruption is a complicated enemy. American officers may want to remove or marginalize shady local officials such as Col. Abdul Razziq, the 33-year-old police commander in the town of Spin Boldak. Yet, when that goal comes up against other imperatives — maintaining short-term security, gathering intelligence on the Taliban or moving supply trucks over the border — fighting corruption often loses out.