Nato has taken a major step in its drive for eastward expansion, with the ambassadors of the 19 member countries signing accession documents to accept seven more members.
Applicants were told the rift over Iraq would not halt expansion plans
The foreign ministers of Bulgaria, Romania, Slovenia, Slovakia, Estonia, Latvia and Lithuania came to Brussels to attend the ceremony at alliance headquarters.
But the signing has been overshadowed by the war in Iraq.
This expansion, the biggest in Nato history, will push the borders of the alliance to the Black Sea.
It was sponsored by the United States, in its search for allies in the war against terrorism.
In exchange, the seven nations invited to join Nato next year pledged their support for the war in Iraq.
So did Poland, Hungary and the Czech Republic, which joined Nato four years ago.
But the former communist countries got caught in the middle of a fierce transatlantic row, when President Chirac of France lashed out warning them that their pro-American stance could harm their hopes to join the European Union.
As both the EU and Nato struggle to redefine their roles, the Secretary General of Nato, George Robertson, reassured the applicants that the rift would not hinder expansion plans.
They have already taken steps to cut their bloated communist-style armies, to increase their defence spending and to ensure the protection of Nato-classified information.
On Wednesday, they signed up to a timetable for further reforms, not least measures to combat corruption, to be completed before they formally join Nato at a summit in May 2004.
Now that Nato ambassadors have signed the accession protocols, amending the founding treaty of the alliance to allow for new members, national parliaments in all existing and future member countries have a year to ratify the expansion.
Slovenia opened the way last weekend, when 60% of voters said Yes to Nato in a referendum.