Mohamed ElBaradei and the International Atomic Energy Agency, the nuclear watchdog agency he heads, won the 2005 Nobel Prize for Peace today.

The Norwegian Nobel Committee called ElBaradei "an unafraid advocate" for nuclear nonproliferation "at a time when the threat of nuclear arms is again increasing."

ElBaradei, whose ouster was sought by the Bush administration led by controversial United Nations appointee John Bolton, is a longstanding critic of the president's decision to go to war in Iraq. So was former President Jimmy Carter when he won the prize in 2002, an award widely interpreted as a shot at the Bush administration.

Nonetheless, Secretary of State Condoleezza Rice issued a statement this morning congratulating ElBaradei and the IAEA on receiving the peace prize.

"In conferring this well-deserved honor on the IAEA," Rice added, "the Nobel Committee noted, 'At a time when there is a danger that nuclear arms will spread both to states and to terrorist groups, and when nuclear power again appears to be playing an increasingly significant role, IAEA's work is of incalculable importance.' The United States is committed to working with the IAEA to prevent the spread of nuclear weapons technology."

As the recipient of what many consider the world's most prestigious award, ElBaradei joins a pantheon that includes former President Woodrow Wilson, Martin Luther King, Nelson Mandela, the Dalai Lama, Mother Teresa and a host of agencies connected, like the IAEA, with the United Nations, including the U.N. itself and Secretary General Kofi Annan.

Nuclear weaponry, and peacemaking, have been the constant themes of the awards, created by the will of Alfred Nobel, the Swede given credit for the development of dynamite.

The Norwegian Nobel Committee cited ElBaradei and the IAEA "for their efforts to prevent nuclear energy from being used for military purposes and to ensure that nuclear energy for peaceful purposes is used in the safest possible way."

The Vienna-based IAEA, established under U.N. auspices in 1957, coordinates nuclear safety around the world and monitors materials that could be diverted for weapons use. It has played pivotal investigative roles in four major crises in recent years: Iran, Iraq, North Korea and the nuclear black market run by one of Pakistan's top scientists.

"The award sends a very strong message," the new laureate said at a news conference in Vienna. " 'Keep doing what you are doing -- be impartial, act with integrity', and that is what we intend to do.

"The advantage of having this recognition today," ElBaradei said, "is that it will strengthen my resolve. The fact that there is overwhelming public support for our work definitely will help to resolve some of the major outstanding issues we are facing today, including North Korea, including Iran and nuclear disarmament.

"It is a responsibility, but it is also a shot in the arm," he said.

Despite the fact that the United States helped install ElBaradei in his job eight years ago, ElBaradei's refusal in 2003 to confirm White House allegations that Iraq's Saddam Hussein had rebuilt his nuclear weapons program lost ElBaradei the U.S. support he had enjoyed.

In an interview with The Washington Post last fall, ElBaradei said the day the United States invaded Iraq "was the saddest in my life." It was not because he was a fan of Hussein, but because he was so sure Washington's assertions about weapons stockpiles and a secret program would be proved wrong.

Washington responded to ElBaradei's findings on Iraq's alleged weapons of mass destruction by trying to prevent him from taking a third term, despite requests from other board members that he stay on. "I am staying because I was asked, because so many board members made me feel guilty about leaving at such a crucial time," he said in an interview earlier this year.

The Bush administration launched a vigorous but solitary campaign -- including a complete halt of intelligence sharing, recruitment of potential replacements for ElBaradei and eavesdropping on him in search of ammunition against him. But as his popularity diminished in Washington, it soared elsewhere.

Nobel Committee chairman Ole Danbolt Mjoes said the prize was not a veiled criticism of Washington, wire services reported.

"This is not a kick in the legs to any country," he told a news conference. A former chairman had described the 2002 prize to Carter as a "kick in the legs" to Bush.

One expert said the prize would have been less controversial if it had gone to the IAEA alone. ElBaradei's inclusion "is an implicit criticism of the United States," said Stein Toennesson, head of the Peace Research Institute, Oslo.

ElBaradei was virtually unknown when the United States engineered his candidacy eight years ago to run the U.N.'s nuclear watchdog agency. He was a soft-spoken lawyer then, who left the Middle East of his youth for New York, first as a diplomat, then as an academic and finally as a career U.N. servant.

"What more could we ask for than a smart, respected Egyptian who cares passionately about the New York Knicks and nuclear nonproliferation?" said John Ritch, a former U.S. ambassador to the IAEA who was instrumental in ElBaradei's selection.

Though ElBaradei lacked any experience leading a major institution, U.S. support was enough for him to beat the only other contender -- a South Korean whose own country abstained -- in a 34 to 0 vote that launched ElBaradei's tenure as director general of the IAEA.

ElBaradei became a champion in the eyes of many who opposed the war in Iraq, especially those in the Arab world. He is often asked for autographs, and occasionally applauded, when he lands in Arab capitals and is one of the most sought-after officials for media interviews.

Privately, Bush administration officials acknowledge that the IAEA's Iran investigation, now in its third year, has been thorough and that the agency has uncovered far more than U.S. intelligence could have learned without it.

The work and the war have changed ElBaradei, who is 63. He still shuns the social circuit and prefers to spend most evenings at home with his wife in Vienna, but he has become far more vocal in recent years.