THE DEAL.

On February 4th, Dr. Abdul Qadeer Khan, who is revered in Pakistan as the father of the country's nuclear bomb, appeared on a state-run television network in Islamabad and confessed that he had been solely responsible for operating an international black market in nuclear-weapons materials. His confession was accepted by a stony-faced Pervez Musharraf, Pakistan's President, who is a former Army general, and who dressed for the occasion in commando fatigues. The next day, on television again, Musharraf, who claimed to be shocked by Khan's misdeeds, nonetheless pardoned him, citing his service to Pakistan (he called Khan "my hero"). Musharraf told the Times that he had received a specific accounting of Khan's activities in Iran, North Korea, and Malaysia from the United States only last October. "If they knew earlier, they should have told us," he said. "Maybe a lot of things would not have happened."

It was a make-believe performance in a make-believe capital. In interviews last month in Islamabad, a planned city built four decades ago, politicians, diplomats, and nuclear experts dismissed the Khan confession and the Musharraf pardon with expressions of scorn and disbelief. For two decades, journalists and American and European intelligence agencies have linked Khan and the Pakistani intelligence service, the I.S.I. (Inter-Service Intelligence), to nuclear-technology transfers, and it was hard to credit the idea that the government Khan served had been oblivious. "It is state propaganda," Samina Ahmed, the director of the Islamabad office of the International Crisis Group, a nongovernmental organization that studies conflict resolution, told me. "The deal is that Khan doesn't tell what he knows. Everybody is lying. The tragedy of this whole affair is that it doesn't serve anybody's needs." Mushahid Hussain Sayed, who is a member of the Pakistani senate, said with a laugh, "America needed an offering to the gods--blood on the floor. Musharraf told A.Q., 'Bend over for a spanking.' "

A Bush Administration intelligence officer with years of experience in nonproliferation issues told me last month, "One thing we do know is that this was not a rogue operation. Suppose Edward Teller had suddenly decided to spread nuclear technology and equipment around the world. Do you really think he could do that without the government knowing? How do you get missiles from North Korea to Pakistan? Do you think A.Q. shipped all the centrifuges by Federal Express? The military has to be involved, at high levels." The intelligence officer went on, "We had every opportunity to put a stop to the A. Q. Khan network fifteen years ago. Some of those involved today in the smuggling are the children of those we knew about in the eighties. It's the second generation now."

In public, the Bush Administration accepted the pardon at face value. Within hours of Musharraf's television appearance, Richard Armitage, the Deputy Secretary of State, praised him as "the right man at the right time." Armitage added that Pakistan had been "very forthright in the last several years with us about proliferation." A White House spokesman said that the Administration valued Musharraf's assurances that "Pakistan was not involved in any of the proliferation activity." A State Department spokesman said that how to deal with Khan was "a matter for Pakistan to decide."

Musharraf, who seized power in a coup d'etat in 1999, has been a major ally of the Bush Administration in the war on terrorism. According to past and present military and intelligence officials, however, Washington's support for the pardon of Khan was predicated on what Musharraf has agreed to do next: look the other way as the U.S. hunts for Osama bin Laden in a tribal area of northwest Pakistan dominated by the forbidding Hindu Kush mountain range, where he is believed to be operating. American commanders have been eager for permission to conduct major sweeps in the Hindu Kush for some time, and Musharraf has repeatedly refused them. Now, with Musharraf's agreement, the Administration has authorized a major spring offensive that will involve the movement of thousands of American troops.

Musharraf has proffered other help as well. A former senior intelligence official said to me, "Musharraf told us, 'We've got guys inside. The people who provide fresh fruits and vegetables and herd the goats' " for bin Laden and his Al Qaeda followers. "It's a quid pro quo: we're going to get our troops inside Pakistan in ...