The Wikileaks "Afghan War Dairy" documents the problems encountered by Afghans and the allied forces in 2004-2009. The war effort was under-resourced. Troops were spread too thin. Intelligence officers within our supposed ally Pakistan were actively assisting the Taliban.

But the Pentagon has since charted a new Afghan strategy to overcome these problems. It would be a shame to abandon the new, reality-based strategy before it has a chance to succeed. It would be dangerous, as well.

The leaked documents discuss the weakness and lack of accountability among government institutions throughout the region. These are the same problems that made the 9/11 attack possible.

South Asia became a breeding ground for global terrorism precisely because local police and security forces lacked the capacity to combat terrorism and because elements of the Pakistani intelligence community supported both the Afghan Taliban and the insurgency in Kashmir.

Al-Qaeda flourished in this environment. Its international campaign of murder and mayhem knew no bounds.

Since then, the American-led counteroffensive has done much to turn back the Islamist tide. The Taliban and al-Qaeda have been dislodged from their Afghan strongholds, their leadership decimated and their focus switched to defense rather than offense. On almost every other front - from Australia to Indonesia to the Philippines -the violent extremist threat has been diminished as well.

Still the evil is out there. In Pakistan, al-Qaeda is hanging on. Meanwhile its allies like the Pakistani Taliban and Lashkar-e-Taiba (LeT) have become forces to be reckoned with. India remains at risk because groups such as LeT - which conducted the 2008 Mumbai attacks - can overmatch local police units.

The U.S. and its NATO allies cannot walk away from Afghanistan before that nation builds the institutions needed to defend and govern itself. To bail out before then is to issue the Taliban an invitation to return to power and start breeding terrorism anew.

For Afghanistan, the return of the Taliban will mean a new civil war, at best, and perhaps a genocide. Al-Qaeda will be back with a vengeance. A new wave of terrorism will sweep across South Asia, while groups such LeT and al-Qaeda plan the next 9-11. Nuclear-armed Pakistan and India could come to blows.

In sum, this would be a world far more hazardous than the one we live in now. But we don't need to turn our backs on Afghanistan. This is a war that can be won.

While the president's timeline for withdrawing U.S. forces in 2011 is completely unrealistic, the military's new strategy is sound. Taking the fight to the enemy, taking away space for the Taliban to operate and standing-up the capacity for security and governance so the Taliban cannot return makes sense. The United States also needs to work more closely with India which must vastly improve the professionalism and capacity of its police forces and counterterrorism units Of course, the United States must continue to press Pakistan to take on all the violent extremists in its lands. And with an Afghanistan that can defend itself and an India less susceptible to terrorism, Pakistan will have little choice. The people of Pakistan find themselves under escalating attack from domestic terrorists intent on destroying democracy and secular institutions. Pakistani officials will find tolerating terrorism becomes increasingly intolerable once the war in Afghanistan is won.

Fighting terrorists in South Asia is not easy. But it is a worthwhile effort that offers the promise of a more enduring peace and a safer world for our civilians and allies. Now is the time to vanquish al-Qaeda and its affiliates, not give them a second lease on life. Running away would end nothing. Indeed, it would be but the prelude to more 9-11 style misery.

James Jay Carafano is senior research fellow for national and homeland security at the Heritage Foundation.