By Greg Miller and Joby Warrick
Saturday, February 19, 2011; A08
A comprehensive new U.S. intelligence report concludes that Iran has resumed research on key components for a nuclear weapon, but that the slow and scattered nature of the effort reflects renewed debate within the government over whether to build a bomb, U.S. officials said.
The finding represents a significant, if subtle, shift from the main conclusion of a controversial 2007 estimate that Iran had halted its weaponization work.
In finding that Iran has again begun taking steps toward designing a nuclear warhead, the new estimate is likely to be seen as erasing doubt that the earlier document created about Iran's intent.
But the new report reaches no firm conclusions about when Iran might acquire the bomb. The classified estimate has already triggered debate among American officials over whether Iran's apparent hesitation is the result of U.S.-backed sanctions meant to derail any weapons program.
Overall, the National Intelligence Estimate concludes that Iran is conducting "early-stage R&D work on aspects of the manufacturing process for a nuclear weapon," said a U.S. official familiar with the report. At the same time, the estimate describes "serious debate within the Iranian regime . . . on how to proceed."
Anticipation surrounding the new estimate has been intense, not only because it addresses one of the central national security dilemmas confronting President Obama, but also because critics regarded the previous estimate as confusing, and blamed it for undermining then-President George W. Bush's efforts to ratchet up diplomatic pressure on Iran.
The report carries weight because it represents the consensus view of the entire U.S. intelligence community, rather than the assessments of a lone agency.
U.S. officials have said that, unlike the estimate of four years ago, the new one will remain classified and out of public view; they would describe it only on the condition of anonymity. A Wall Street Journal article described aspects of the estimate this week.
Director of National Intelligence James R. Clapper Jr. summarized key points in testimony before the Senate intelligence committee Wednesday, telling lawmakers that Iran's "technical advancement, particularly in uranium enrichment, strengthens our assessment that Iran has the scientific, technical and industrial capacity to eventually produce nuclear weapons." He added, "Iran is technically capable of producing enough highly enriched uranium for a weapon in the next few years. Whether such a decision to do so had been made, he said, is unclear.
The new assessment does not entirely refute the 2007 report's most controversial finding, which held that Iran's leaders had halted nuclear weaponization research in 2003, even while pushing forward on uranium enrichment that is regarded as the most difficult step to building a bomb.
U.S. spy agencies remain convinced that Iranian officials ordered a temporary halt to certain military research projects aimed at mastering the complex engineering involved in building nuclear warheads. The stoppage was described in computer notes and files surreptitiously obtained by the United States.
At the time, Iran's massive enrichment plant near Natanz had been exposed by an opposition group. The halt also coincided with the U.S.-led invasion of Iraq.
"After 2003 the program went to ground," said a senior administration official who has reviewed the latest estimate. But even while that military-backed project remains shuttered, the official said, the effort "became not a single program but multiple programs farmed out to universities and private companies. What research is being carried out, and to what end, is now much harder to pin down."
Many analysts believe that Iran intends to follow the same course as Japan and other states that are regarded as "virtual" nuclear powers - acquiring all the basic building blocks for nuclear weapons without actually building a bomb.
These analysts believe Iran would stop short of assembling and testing a bomb, a move that would subject the country to international condemnation and a possible military attack. Iran consistently denies having a nuclear weapons program.
Over the past year, U.S. intelligence officials have become increasingly convinced that Iran's progress toward building a bomb has suffered setbacks, giving the United States and its allies an additional cushion of two years or more before Tehran would be in position to test a device.
Delays to Iran's program have been attributed in part to elaborate attempts at sabotage, including the unleashing of a computer worm, called Stuxnet, that caused major equipment failures in centrifuge machines at Natanz. U.N. inspectors have concluded that hundreds of machines failed in the attack but that Iran recovered remarkably quickly, wheeling in new machines.
U.S. intelligence agencies believe Iran has continued to achieve progress in making low-enriched uranium, a key ingredient in fuel for commercial nuclear reactors.