Nato's ebullient secretary general, Lord Robertson, was in fine form, declaring a new Nato had been established, insisting there had been real change and reform and not just rhetoric.
Terms like flexibility, relevance, adaptability, have been bandied around at Nato meetings for years, ever since the cold war ended.
Now at long last change does seem to be taking place.
But the alliance has been through difficult times and more stormy waters could lie ahead.
So how true is Lord Robertson's assertion that a new Nato really is emerging from within the old cold war anti-soviet alliance?
Lord Robertson was bluntly honest.
He acknowledged that he has sometimes fought this campaign to construct a new alliance largely on his own.
He may not have been a prophet in the wilderness, but at times he certainly did appear as a lone enthusiastic voice in a sea of inertia.
If a new Nato is emerging then it owns its birth in large part to this Scottish Labour politician's untiring efforts and enthusiasm.
Lord Robertson steps down as Nato's most senior official at the end of this year and he will leave an alliance that is well on the way to constructing and deploying new forces, new headquarters and new operational doctrines.
This week's meeting of Nato defence ministers in Brussels marks an important milestone.
The ministers agreed on a new streamlined command structure.
Some 20 headquarters will be reduced to 11 command centres.
Many of these will be mobile headquarters, capable of deploying to trouble spots quickly, often a long way from Nato's borders.
At the alliance's highest or strategic level, there will only be a single headquarters - SHAPE, or the Supreme Headquarters Allied Powers Europe, based at Mons in Belgium.
The parallel Atlantic Command at Norfolk, Virginia becomes a new kind of organisation, responsible for the transformation of Nato forces.
In addition there will be a number of new training centres, one of which will be in Poland.
There was a fair bit of give and take in agreeing to this new structure.
The alliance had to take into account national sensitivities about status and jobs, as well as the new pattern of threats facing the organisation.
Have additional facilities been added in?
Spain has won an air operations training centre and there are proposals for a similar maritime interdiction or interception centre in Greece.
But in terms of how large international organisations work, these are seen by insiders as minor concessions.
Quite why the major transformation command will be in Virginia, USA is more of a mystery, as most of the forces which need to transform are those of the alliance's European members.
But the US remains the alliance's major player, and that's where most of the thinking and doctrine for the new Nato forces will be developed.
Nato is also making progress in developing its own rapid reaction force, and while more work needs to be done in more areas, the alliance is making steps to improve its capabilities.
The defence ministers, for example, have agreed the outline of an interim plan to lease Ukrainian Antonov transport aircraft to fill a gap in strategic lift until the new European Airbus military transport is flying.
That's the good news, but there are also problems.
"Coalitions of the willing"
A new Nato is a larger Nato.
Potential members are still queuing up to join.
Size means the internal chemistry of the alliance is changing.
While political consensus will still be needed to mount Nato operations, actual missions may be carried out by more restricted "coalitions of the willing", from both within and beyond Nato's ranks.
Many of the alliance's future problems will be political as well as military.
It needs to deal with the inevitable differences in its own ranks, now the cold war is over, differences that were highlighted by the US led war on Iraq.
A new role
A new Nato will be a more complex Nato.
But for those who doubt that change is under way, Lord Robertson set out a list of Nato's developing responsibilities.
Counter terrorism, Balkan peacekeeping, and soon, command of the international stabilisation force in the Afghan capital, Kabul.
Nato will soon be helping Poland to carry out its mission in Iraq.
Nato's horizons are changing dramatically.
There's no room for complacency.
At root, Nato's success rests on the state of the transatlantic relationship between the US and Europe.
So Nato's future promises to be as bumpy as its recent past.