WASHINGTON, Dec. 3 — Rarely, if ever, has a single intelligence report so completely, so suddenly, and so surprisingly altered a foreign policy debate here.
An administration that had cited Iran’s pursuit of nuclear weapons as the rationale for an aggressive foreign policy — as an attempt to head off World War III, as President Bush himself put it only weeks ago — now has in its hands a classified document that undercuts much of the foundation for that approach.
The impact of the National Intelligence Estimate’s conclusion — that Iran had halted a military program in 2003, though it continues to enrich uranium, ostensibly for peaceful uses — will be felt in endless ways at home and abroad.
It will certainly weaken international support for tougher sanctions against Iran, as a senior administration official grudgingly acknowledged. And it will raise questions, again, about the integrity of America’s beleaguered intelligence agencies, including whether what are now acknowledged to have been overstatements about Iran’s intentions in a 2005 assessment reflected poor tradecraft or political pressure.
Seldom do those agencies vindicate irascible foreign leaders like President Vladimir V. Putin of Russia, who several weeks ago said there was “no evidence” that Iran was building a nuclear weapon, dismissing the American claims as exaggerated.
The biggest change, though, could be its effect on President Bush’s last year in office, as well as on the campaign to replace him. Until Monday, 2008 seemed to be a year destined to be consumed, at least when it comes to foreign policy, by the prospects of confrontation with Iran.
There are still hawks in the administration, Vice President Dick Cheney chief among them, who view Iran with deep suspicion. But for now at least, the main argument for a military conflict with Iran — widely rumored and feared, judging by antiwar protesters that often greet Mr. Bush during his travels — is off the table for the foreseeable future.
As Senator Chuck Hagel, Republican of Nebraska, put it, the intelligence finding removes, “if nothing else, the urgency that we have to attack Iran, or knock out facilities.” He added: “I don’t think you can overstate the importance of this.”
The White House struggled to portray the estimate as a validation of Mr. Bush’s strategy, a contention that required swimming against the tide of Mr. Bush’s and Mr. Cheney’s occasionally apocalyptic language.
The national security adviser, Stephen J. Hadley, said the estimate showed that suspicions about Iran’s intentions were warranted, given that it had a weapons program in the first place.
“On balance, the estimate is good news,” Mr. Hadley said, appearing at the White House. “On one hand, it confirms that we were right to be worried about Iran seeking to develop nuclear weapons. On the other hand, it tells us that we have made some progress in trying to ensure that that does not happen. But it also tells us that the risk of Iran acquiring a nuclear weapon remains a very serious problem.”
Mr. Hadley insisted, as he and others have, that the administration had hoped and still hoped to resolve the outstanding questions about Iran’s nuclear programs using diplomacy, not force. But the nuances of his on-this-hand-on-the-other argument will probably make it much harder to persuade American allies to accept the administration’s harder line.
One official pointed out that the chief American diplomat on the Iran question, Under Secretary of State R. Nicholas Burns, had just met with counterparts from Europe, Russia and China, and had seemed to make some headway on winning support for a third round of sanctions by the United Nations Security Council. The official said Mr. Burns could not divulge the intelligence findings at that meeting on Friday because Congress had not been briefed.
The immediate task for Mr. Burns and other administration officials is to untangle the confusion caused by its own statements and findings and to persuade skeptics that this time, the United States has it right about what Iran was doing before 2003 and what that means for what it might do in the future.
“The way this will play is that the intelligence community has admitted it was wrong,” said Jon B. Alterman of the Center for Strategic and International Studies. “So why should we believe them now?”
Mr. Hadley said the drastic reversal in the intelligence agencies’ knowledge about Iran’s weapons programs was based “on new intelligence, some of which has been received in the last few months.”
With some of the administration’s most prominent hawks having departed and not taking part in the review of findings like these, it is possible that the zeal for another military conflict has diminished. After all, the first two wars on Mr. Bush’s watch remain unresolved at best.
Senator Hagel said he hoped that the administration might in its final year in office show the kind of diplomatic flexibility it did with North Korea over its nuclear weapons or with the conference in Annapolis, Md., last week on the Israeli-Palestinian conflict. He has previously called for the United States to open direct and unconditional talks with Iran to end the state of enmity that has existed since 1979.
He said Iran’s halt of weapons activity had created an opening for such talks, indicating, as the assessment does, that Iran’s government may be more rational than the one that Mr. Bush said in August had threatened to put the entire region “under the shadow of a nuclear holocaust.”
“If we’re wise here, if we’re careful, I think we have some opportunities,” Mr. Hagel said.
The findings, though, remain open for interpretation, as they always do, even in documents meant to reflect the consensus of the intelligence community. When it comes to Iran, at odds with the United States on many fronts beyond the nuclear question, hawks remain.
“Those who are suspicious of diplomacy are well dug in in this administration,” said Kurt M. Campbell, chief executive officer of the Center for a New American Security.
John R. Bolton, the former ambassador to the United Nations, who recently left the administration and began to criticize it, sounded very much like Mr. Hadley on Monday, saying the assessment underscored the need for American toughness. He said Iran’s intentions would always remain a concern as long as it continued to enrich uranium.
“The decision to weaponize and at what point is a judgment in the hands of the Iranians,” he said. He added that the finding that Iran halted a weapons program could just mean that it was better hidden now.