Next week, President Obama will meet the leaders of Pakistan and Afghanistan in the White House. He'll have his work cut out for him. Increasingly, Pakistan holds the key not only to success in Afghanistan, but to peace in the entire South Asia region.

Pakistan is undergoing profound social and political changes that could explode into a full-blown Islamist revolution. The threat arises from not just its double dealing with the Taliban in Afghanistan, but also the Islamist insurgency in its northwest spreading to other areas and undermining state authority.

Mr. Obama surely understands the severity of the crisis, but it is not clear that he knows what to do about it. His administration has rightly sounded that alarm, sent a steady stream of senior officials to Pakistan to try to shore up its response to the threat and pressured Congress to expedite both military and economic aid. These may be good stopgap measures, but the administration must develop a more coherent, longer-term strategy on Pakistan.

Earlier in April, President Asif Ali Zardari approved a peace deal with pro-Taliban militants that included the establishment of a parallel Islamic courts system in parts of the North West Frontier Province (NWFP). That surrender yields two lessons.

First, the weakness of the Pakistani army. Some 12,000 Pakistani troops gave up to about 3,500 insurgents in the Swat Valley last year, partly to avoid fighting their own people and partly because there are mixed loyalties within the army, particularly among the 25 percent who are Pashtun. Second, the surrender directly flouts a democratic mandate. NWFP voters, especially those in Swat Valley, overwhelmingly backed the secular Awami National Party in the February 2008 national elections.

This capitulation to the Taliban was a stain on the Pakistani military for not protecting the sovereignty of state authority and the rule of law. It also was a direct overthrow of the legitimate will of the people. Essentially, it abandoned them to a violent, extremist minority who do such things as bomb girls' schools,kill women who want to work and publicly behead people falsely accused of spying.

Recent events appear to have awakened some Pakistani officials to the seriousness of the predicament. Taliban forces from the Swat Valley tried to take over a neighboring district, Buner, but have since agreed to withdraw after Pakistan deployed paramilitary troops to the region. army chief Gen. Ashfaq Kiyani warned the militants that the military's "pause in operations" should not be read as a concession and that the army would "not allow the militants to dictate terms to the government or impose their way of life on the civil society of Pakistan."

The statement helped clarify Pakistani policy toward the militants. Now, it must be followed by sustained, comprehensive action that counters Taliban objectives.

With the situation in Pakistan so fluid, any false move by Mr. Obama could have dire consequences. Some suggest that the U.S. play a more active role in Pakistan's domestic internal politics by signaling support for former Prime Minister Nawaz Sharif as an alternative to Mr. Zardari. This would be a huge mistake.

The U.S. helped defuse a recent political crisis between these two, but Washington should not personalize politics in Pakistan. Instead, it should pursue a consistent policy of supporting democratic institutions and processes. The U.S. is still widely resented in Pakistan for supporting former Pakistani President Pervez Musharraf, who stifled democracy for years.

The other temptation would be to sacrifice U.S.-India relations on the altar of promised Pakistani support for U.S. efforts in Afghanistan. Pakistan's armed forces would like the U.S. to be more directly involved in resolving the Kashmir dispute and to pressure India to make concessions. This would damage U.S. ties to India and could further destabilize the Kashmir region by raising false expectations and giving extremists reason to increase violence to push an agenda they think is within reach.

Instead, the U.S. should quietly prod both sides to resume their dialogue, which made substantial progress from 2004 to 2007, and seek to persuade Pakistani security and intelligence services to stop supporting militants fighting in Kashmir.

Above all, Mr. Obama needs to find a way to get the Pakistani army and intelligence services off the fence in fighting the Taliban. This is no easy task. It will require more than words and meetings with high-level envoys. A key leverage point is military aid. Continued multiyear U.S. military aid should be conditioned on Pakistani cooperation in fighting terrorists and militants. Militant groups in the Punjab region pose increasing threats to regional stability, as evidenced by last year's attacks in Mumbai.

Some will argue that conditioning military aid could signal a U.S. abandonment of Pakistan. If managed carefully, we can avoid sending such a signal. Gen. David H. Petraeus, commander of U.S. Central Command, for example, should be given maximum flexibility to provide U.S. counterinsurgency assistance to Pakistan to help it resist Taliban advances and determine whether we can more effectively partner with Pakistan to counter terrorist threats in the region. Aid conditions could also be fashioned to exempt specific programs designed to assist in counterinsurgency warfare along the Afghanistan-Pakistan border.

Attaching conditions to multiyear U.S. military aid is necessary to firm up Pakistan's response to the terrorist scourge that threatens to engulf the country. The military's mixed policies toward the Taliban contributed to a situation that threatens Pakistan's integrity as a state.

Anything we do to reinforce this fact to Islamabad would be doing the Pakistani people, not to mention the rest of the world, an enormous favor.