Mr. Mohamed ElBaradei and the International Atomic Energy Agency (IAEA), the nuclear watchdog agency that he leads, are the winners of the 2005 Nobel Peace Prize. The award underscores the critical significance of the work done by Mr. ElBaradei and the IAEA. But given the events of the last year, it is plain that the recognition is for the effort that has been made by the recipients, rather than the results of their work -- and to remind the world that the IAEA chief, and the agency itself, are increasingly vital components of the international security order.

Founded in 1957, the IAEA is part of the United Nations system. The agency is tasked with ensuring that the bargain in the Nuclear Nonproliferation Treaty (NPT) -- the provision of nuclear technology to signatories in exchange for giving up the right to nuclear weapons -- is honored. Throughout most of its history, its employees have labored in obscurity, focusing on technical work, usually inspections. That low profile ended in the 1990s, when the invasion of Iraq uncovered an advanced nuclear-weapons development program and North Korea brought the world to the brink of war with revelations about its own clandestine nuclear-weapons efforts.

Since then, the prospect of nuclear proliferation has loomed ever larger and the loopholes in the NPT have become increasingly clear. Efforts to close them have provoked political firestorms among IAEA members and within the agency itself. One of the most notable clashes has been between the United States and Mr. ElBaradei over Iraq. The IAEA head maintained that Baghdad did not have the nuclear-weapons programs that justified the U.S. decision to invade Iraq. The subsequent discovery that he was right, and Washington wrong, did not help soothe tensions between the two. The U.S. bitterly opposed Mr. ElBaradei when he ran for a third term in office -- even though it had engineered his initial appointment as director general eight years ago -- until it become clear that he would be re-elected.