The sudden announcement that Libya is giving up its ambitions to develop weapons of mass destruction is a major step in the effort led by the United States to stop their spread around the world.
Libya is trying to repair international relations
The move by Colonel Muammar Gaddafi and the capture of Saddam Hussein are two very welcome seasonal presents for President Bush and Prime Minister Blair.
It was natural that they should both have rushed in front of the cameras to make the announcement, a race which Mr Blair narrowly won.
It helps to soften the disappointment of failing to find weapons in Iraq.
And it shows that countries can be persuaded not to go down the path of developing these weapons.
The message to North Korea and Iran in particular is clear. If you co-operate, there will be rewards. If you do not, there will be dangers.
Colonel Gaddafi appears to have got the message of Iraq - that developing such weapons or even showing an interest in them is highly dangerous.
He was ready for such a move, which Mr Blair revealed came at the Libyan leader's own initiative in March, the very moment when Saddam Hussein was being driven out of power.
At the same time, Libya signalled that it was ready to pay compensation for the Lockerbie bomb, which it did in August.
United Nations sanctions were lifted and Colonel Gaddafi began to come in from the cold. He had seen which way the wind was blowing.
Given what happened to Saddam Hussein, Colonel Muammar Gaddafi can reckon himself fortunate to have got away with, in effect, a fine.
At the time, the US deputy UN ambassador James Cunningham said that the vote "must not be misconstrued by Libya or by the world community as tacit US acceptance that the government of Libya has rehabilitated itself.
"The United States continues to have serious concerns about other aspects of Libyan behaviour, including its poor human rights record, its rejection of democratic norms and standards, its irresponsible behaviour in Africa, its history of involvement in terrorism and most important, its pursuit of weapons of mass destruction and their means of delivery," he said.
We now know that he was being serious about those weapons and the rockets to go with them.
'Sponsor of terrorism'
It has often been alleged that Libya was trying to develop chemical weapons, though the extent of this programme was unclear.
Mr Bush mentioned biological and nuclear programmes as well. Of those, even less is known.
Until the US is satisfied that the Colonel will live up to his promises, the remaining US sanctions will not be removed.
These are a ban on trade, including oil, and penalties for non-US companies which invest more than $20m a year in Libya's oil industry.
And Washington still classifies Libya as a state sponsor of terrorism.
But Mr Bush also said that the "path is open" to normalising relations, so that will probably come in due course.
It is an amazing turnaround for Colonel Gaddafi, whose own compound was bombed on the orders of Ronald Reagan in 1986.
He has also supplied the IRA with weapons.
Now he is being lauded by both the US and the UK.
Libya remains a major oil producer. It is seventh in the Opec oil cartel's top 10.