How can this be?

Friday, May 22, 2009 | 2:08 a.m.

After a federal audit disclosed in February that record-keeping was inadquate to track U.S. weapons intended for the Afghan National Security Forces, we wrote that the Defense Department should guard against those arms falling into the hands of enemy fighters.

It now turns out that the Pentagon may have to keep better track of ammunition sent to Afghanistan, too.

The New York Times reported Wednesday that cartridges American soldiers retrieved from dead insurgents last month in eastern Afghanistan were identical to ammunition the U.S. and its allies provided to Afghan government forces. Some cartridges had markings that matched those furnished by a California company. Other cartridges resembled surplus Czech ammunition that was also shipped to the Afghan military.

It is bad enough that rebel Taliban forces in Afghanistan have become increasingly difficult to combat, a situation that is one of the toughest foreign policy issues confronting the Obama administration. It is even worse to think there is a possibility that Taliban fighters could use American arms and ammunition to kill or wound U.S. soldiers.

As the Times reported, ammunition is more difficult to trace and can be obtained through corruption, illegal sales, theft or battlefield action. But the Defense Department should develop ways to keep tighter inventory controls on ammunition, as it has vowed to do with weapons sent to Afghanistan.

The U.S. also should do a better job of gathering intelligence to disrupt any black markets or other avenues that could allow Taliban forces to obtain weapons and ammunition intended for Afghan government forces. Compounding matters is that Afghan President Hamid Karzai oversees a corrupt government, a situation that remains untenable.

It is deeply troubling to think that Taliban forces may have been able to fight for as long as they have because they can get their hands on guns and bullets furnished by the U.S. and its allies.