Unprecedented Peril Forces Tough Calls

Bolton described Libya's nuclear disarmament and the exposure of Khan's black market as highlights of the Bush record, and said North Korea and Iran might be further along if not for the administration's tough stand.

"The question is not, 'Is the status of the pursuit of nuclear weapons more advanced?' " he said. "The question is, 'What would have happened and how much worse would it have been if we hadn't pursued a more aggressive policy?' "

Defining that threat, and its source, would top the list of urgent assignments for U.S. intelligence after Sept. 11.

"We thought the highest probability of their getting anything would be to buy a weapon full up" from corrupt or ideologically allied insiders in the chain of custody in a nuclear weapons state, said Richard A. Clarke, who organized the intelligence summit as Bush's national coordinator for counterterrorism. "We assumed the place most likely to supply that would be the former Soviet Union. They had more weapons, and there were more people involved in guarding them, compared to a fairly limited number of weapons in Pakistan that were fairly well accounted for."

Russia's risk factors were widespread corruption, a Chechen insurgency linked to radical Islamists elsewhere, and what Graham Allison, an assistant secretary of defense under Clinton, has called the "Willie Sutton Principle." In a recent book, "Nuclear Terrorism," Allison wrote, "When asked why he robbed banks, Sutton answered: 'Because that's where the money is.' " The logic of deterrence offered two strong reasons, U.S. intelligence judged, to doubt any government would deliberately transfer such a weapon. For one, al Qaeda might turn the bomb against its source. For another, the isotopic signature of a nuclear device can be traced to its country of manufacture, exposing that nation to catastrophic retaliation.

Al Qaeda's behavior suggested it had done much the same market survey. In 1998, in one of several similar cases, Israeli intelligence reported that bin Laden paid more than 2 million pounds to a middleman in Kazakhstan who promised to deliver a stolen warhead -- though there is no evidence that delivery took place.

A National Intelligence Estimate on nontraditional threats, completed long after Bush had committed himself to war in Iraq, reprised earlier judgments. Black-market sales from "the former Soviet Union, Pakistan -- those were the highest risks," said Richard A. Falkenrath, a former White House official who co-wrote Bush's classified May 2002 strategy "Combating Proliferation of Weapons of Mass Destruction."

Bush took a different view. In the State of the Union address of Jan. 29, 2002, the president declared he would keep "the world's most destructive weapons" from al Qaeda and its allies by keeping those weapons from evil governments. Much later -- after applying that doctrine in Iraq -- he told a campaign audience in Pennsylvania, "We had to take a hard look at every place where terrorists might get those weapons and one regime stood out: the dictatorship of Saddam Hussein."

"It was our job to identify the threat as we saw it," said Greg Thielmann, who was director of strategic proliferation and military affairs at the State Department's Bureau of Intelligence and Research until 2003. The White House, he said, "has a right to disagree."

A German-trained metallurgist, Khan had led Pakistan's nuclear weapons program from its infancy. Musharraf's celebration marked Khan's unexpected retirement.

By then, Musharraf had good reason to know Khan was leading a secret life. The U.S. government, very carefully, had told him so.

A combined British-American intelligence inquiry into Khan, among the most closely held secrets of the Bush administration's first year, was progressively surpassing its worst fears. What London and Washington had struck upon -- beginning in Clinton's final year -- was a danger not seen before: a global private marketplace in the makings of a nuclear bomb.