By Paul Reynolds
World Affairs correspondent, BBC News website
Mohamed ElBaradei swung into action over Iran's nuclear activities
The Nobel peace prize for the International Atomic Energy Agency (IAEA) and its director general, Mohamed ElBaradei, is more than a pat on the back.
It is a signal of encouragement from the Nobel committee that negotiation, not confrontation, should be the way forward in nuclear disarmament.
Up until quite recently, the US had questioned whether Mr ElBaradei was tough enough, though in the end it supported him and he was re-appointed to a third term in office last month.
There were some in Washington who worried that the IAEA was not up to the job, as it had missed the secret Iranian effort to develop a nuclear fuel enrichment programme over nearly 20 years, in violation of the Nuclear Non-Proliferation Treaty (NPT).
But once the programme had first been revealed by Iranian exiles, the IAEA and Mr ElBaradei in particular swung into action in a very vigorous way. This led to a report in November 2004 detailing the Iranian violations and laying down a programme under which it would be brought into compliance.
Such actions have obviously impressed the Nobel committee, and the support for the director general on the IAEA board was sufficient to quell American doubts.
Mr ElBaradei's style is very much that of the technocrat, the expert. He is not the skilled international diplomat who can make an impact with his personality. He makes his impact with his expert analysis.
This has been evident in the way that he has pinned Iran down, on issue after issue.
And he has been a fair judge. He has conceded for example that some Iranian arguments have merit - for example, the Iranian claim that some traces of enriched uranium found on smuggled centrifuges must have been on the parts before they arrived in Iran.
So in a long and complex process, he has emerged as a man who cannot be fooled by bogus technical arguments.
More difficult for him to fight against has been the charge that the IAEA was asleep on the job over the spread of the so-called AQ Khan network.
Dr Khan was the father of the Pakistani bomb and he then became the source of supplies and technology for Iran, Libya and possibly North Korea.
There has also been a perception that the IAEA is losing ground in the effort to prevent the spread of nuclear weapons.
North Korea has withdrawn from the NPT treaty and claims to have built nuclear devices already.
India, Pakistan and Israel are not even members, so are free to develop nuclear bombs anyway.
Iran claims it has a right to use nuclear technology for energy
And the NPT, the bastion of the campaign, has proved shaky in the case of Iran.
Nor is the campaign over.
The weak link in the NPT's chain of forts is the right of a country to enrich uranium to a level sufficient for the production of nuclear power. This is what Iran is claiming a right to do.
But the same technology can then be developed to enrich fuel further to the level needed for a nuclear bomb.
For the moment, the IAEA way is the chosen way forward over Iran - technical analysis, international pressure but referral to the Security Council for possible sanctions if need be.
The Nobel committee has given its approval to such methods.
There are other voices. Israel has said that Iran could become its greatest threat - and Israel has a record of taking military action. It destroyed Saddam Hussein's French-supplied reactor in an air attack in 1981.
The peace prize for the IAEA has come at a timely moment.
But some of the most difficult arguments may still lie ahead.
The award could also be seen an indirect criticism of the American approach to the issue of Iraq and weapons of mass destruction.
Mr ElBaradei always argued for more time to be given to the UN inspectors and early on he knocked down one US suspicion, that aluminium tubes were for fuel enrichment centrifuges.
He said, as Iraq claimed, they were probably for rocket barrels.