One only has to read the Pentagon's progress report on the Afghanistan war effort released Dec. 10 to understand how pointless it is to keep 68,000 American troops there any longer.

The mounting evidence makes it clear that they should be pulled out as soon as it can be done safely, instead of waiting until the end of 2014, the date set by the United States and NATO.

Yet the White House is now signaling that the decision on how quickly they will come home will not be made before next year.

The United States has spent a decade and $39 billion to recruit, train and equip a 350,000-member Afghan security force, including the army and police, which is supposed to defend the country when the Americans leave.

President George W. Bush gave the effort short shrift when he shifted focus to Iraq. But even after President Obama's considerable investment, the Pentagon says that only one of the Afghan National Army's 23 brigades is able to operate independently, without air or other military support from the United States and NATO.

Although the report said Afghan forces are "increasingly taking over responsibility for securing Afghanistan," that doesn't mean keeping troops there will do anything but delay the inevitable.

The additional "surge" of 33,000 American troops in 2009 to drive the Taliban from their southern stronghold to the negotiating table weakened the extremists. But they remain "adaptive and determined" and able to conduct "isolated high-profile attacks," the report said.

Negotiations have gotten nowhere.

The United States has made mistakes in Afghanistan. But it has also afforded the Afghans a chance to build a better state.

Commitments by the Obama administration and European allies to provide billions of dollars to support the security forces and finance economic development projects should be kept as long as they seem useful.

But Obama should overrule any plan from the military commanders to keep most of the 68,000 troops there through 2014.