Nuclear designs found with smugglers spur U.S. fears

WASHINGTON (Reuters) - A nuclear watchdog's report that sophisticated warhead designs were found on the computers of Swiss smugglers has spurred fears in the Bush administration and elsewhere that atomic secrets may be quickly spreading.

The report on Monday raised particular speculation over the significance of a U.S. intelligence finding last year that Iran had suspended a nuclear-weapons design program in 2003 -- which slowed a Bush administration drive to confront Iran.

If the Islamic Republic had access to detailed warhead designs on a nuclear black market, that could free it from having to develop its own blueprints for a weapons program.

"That's a question to be studied," a senior U.S. official said. But he said he had little information beyond the public accounts of the report, issued by the Institute for Science and International Security.

"In a general sense there is always a concern that a rogue nation or group that is intent on obtaining nuclear weapons might have been given information that speeds up the development process," the official said.

The CIA and State Department declined comment. Iran says its nuclear program is intended only for peaceful energy.

The institute said Swiss investigators in 2004 found the encrypted designs on computers of three Swiss smugglers associated with A.Q. Khan, considered the father of Pakistan's nuclear program.

Khan in 2004 admitted to unauthorized sales of nuclear technology to Iran, Libya and North Korea, but ABC News reported last month that Khan recanted in an interview.

The designs on the Swiss computers were smaller and more sophisticated than one Libya bought from Khan and would fit on a ballistic missile, ISIS said. "These would have been ideal for two of Khan's other customers, Iran and North Korea," it said.

It cited a senior official of the U.N. nuclear watchdog, the International Atomic Energy Agency, as doubting the three Swiss were the only ones with the designs. The report gave no indication of whether Iran or North Korea had the designs.

Under a 2005 multilateral agreement, North Korea promised to abandon its nuclear programs in exchange for diplomatic and economic benefits, although Pyongyang has yet to produce a promised declaration of its activities.

INTERNATIONAL PRESSURE

Iran has defended its right to conduct a civilian nuclear program. It has defied Bush administration attempts to orchestrate international pressure against Iran to stop developing a capacity to enrich uranium, which can be used in nuclear weapons.

A U.S. National Intelligence Estimate last year reported that Iran had stopped design work on nuclear devices in 2003. It said Iran was pressing ahead with uranium enrichment and missile development but the finding that design work had stopped stalled the momentum of U.S. efforts to confront Iran.

Top U.S. intelligence officials have emphasized that design work could be quickly resumed and the real obstacle to nuclear weapons capacity was a sufficient supply of nuclear fuel.

Despite that, obtaining detailed nuclear weapons blueprints could be a major step forward for Iran or another group or country seeking an arms capacity, said Ivan Oelrich, vice president of strategic security for the Federation of American Scientists.

"The physics of nuclear weapons is no secret ... but there are secrets involved in the engineering of nuclear weapons," Oelrich said. He said a proliferation of detailed designs "could be extremely serious."

White House national security adviser Stephen Hadley said on Sunday that the United States has been concerned that Khan may have spread nuclear weapons technology along with uranium enrichment technology.

"We're very concerned about the A.Q. Khan network, both in terms of what they were doing by purveying enrichment technology and also the possibility that there would be weapons-related technology associated with it," Hadley told reporters.

Daryl Kimball, executive director of the Arms Control Association, said the United States needs to pressure Pakistan's new government to let the IAEA interview Khan.

"There is more of this to track down," he said.

Pakistan said it considers its investigation of Khan to be closed.

(Additional reporting by Susan Cornwell in Washington and Mark Heinrich in Vienna; Editing by Bill Trott)