Danielle Pletka, vice president for foreign and defense policy studies

More than 60 are dead in the ashes of the Islamabad Marriott, hundreds wounded. The hotel, a Western haven, has been a small oasis of normalcy in a country that is slowly collapsing under the weight of years of bad decisions. It didn't require a crystal ball to see the attack, likely the work of Al Qaeda or a close affiliate, coming. It was destiny--the meeting of the cognitive, political and military dissonance that is modern Pakistan.

Pakistan is today where it would have been had 9/11 never happened. Ironically, that attack, planned by terrorists in a safe haven created with the requisite support of Pakistani government and intelligence agencies, saved Pakistan from the consequence of decades of strategic misjudgment.

In the 1980s, indispensable Pakistan was the key to the defeat of the Soviet Union in Afghanistan. How else would Ronald Reagan and Charlie Wilson have won that war? Only with the help of the British-veneered, American-educated Pakistani military and the creative Inter-Services Intelligence Directorate. And if Pakistan was funneling money to the worst of the mujahedin in Pakistan, so what? After all, what was it to us if Gulbuddin Hekmatyar rather than Ahmad Shah Massoud blew a Soviet helicopter out of the sky?

Sadly, the '90s brought a more dispensable Pakistan. Those bad traits Washington had willfully ignored in the '80s were all too troubling in the post-Cold War peace we had earned. Suddenly, the mujahedin looked like a questionable investment, and none more than the Islamist loonies that Pakistan appeared to favor. And Pakistan's own nuclear weapons program, blindingly obvious from the mid-'80s, was abruptly a sanctionable offense under U.S. law. All aid was cut off in 1995.

The next decade might have brought more misery for the once-vibrant Washington-Islamabad partnership had it not been for the rise of Al Qaeda. U.S.-India relations, anathema in the old zero-sum construct of the subcontinent, were warming up. Disapprobation over Pakistan's ties with the Taliban, terrorists in India's disputed Kashmir state, and even with Al Qaeda, was increasingly derailing the old alliance.

But the attacks of 9/11 abruptly changed the game. Pakistan was faced with the memorable choice of sticking with the Taliban or being "bombed back to the stone age," as former president Pervez Musharraf asserts then-Deputy Secretary of State Richard Armitage threatened. Threat or not, Musharraf made the right choice. Pakistan turned on the Taliban, and more decisively, on Al Qaeda. Supporters and senior leaders were rounded up. Intelligence was shared. But it didn't last.

The reasons why are varied, and few agree exactly why Pakistan has regressed so badly. Some suggest it was the Bush administration's 2006 handover of command in Afghanistan to NATO forces. Many in Pakistan felt certain this was the prelude to a full-scale abandonment, the post-Soviet redux. Others believed that as Washington took its eye off the ball in South Asia, focusing instead on Iraq, Pakistan would once again need to fend for itself. Still others theorize that Pakistan believes it can use the Taliban to keep American aid flowing.

Whatever the cause, the fundamental miscalculation that lies at the heart of Pakistan's strategic calculus remains the same: Pakistan, the military and intelligence establishment is persuaded, faces an existential threat from India and cannot protect itself without the "strategic depth" that Afghanistan affords. But the proto-modern Afghanistan of Hamid Karzai does not serve; only the more pliant Talibanized Afghanistan can lend itself as a cushion against the expected Indian blow. And if the price of that is allowing what amounts to free reign for Al Qaeda, so be it.

The fact that India appears increasingly uninterested in annihilating Pakistan, or that the Faustian bargain struck between Pakistan's decision-makers and Islamist extremists has undermined the very fabric of the Pakistani state, appears not to have penetrated to key political, military and intelligence officials.

As a result, the Taliban and Al Qaeda now constitute a parallel government in parts of Pakistan. Commitments to eradicate the menace have repeatedly shriveled in the face of determined resistance from terror networks and Taliban shuras reestablished since 2001. Political failure has only exacerbated the problem. Even the return of democratic rule cannot alone rip the Pakistani state from its fate.

Danielle Pletka is the vice president for foreign and defense policy studies at AEI.