By Nick Thorpe BBC Central Europe correspondent

And two of the most enthusiastic new members are Romania and Bulgaria.

There is little resistance to Nato membership in Bulgaria

Such is the popular enthusiasm for Nato membership in Bulgaria, a national holiday has been called for Friday, the 55th anniversary of the founding of the alliance.

But the foreign minister's plan to issue free beer and wine with the Nato insignia on the labels had to be cancelled after bureaucrats in Brussels complained that this was inappropriate.

Instead, a special 50 stotinky coin, worth about a quarter of a euro, has been issued.

Training and peacekeeping

On the downside, there is little organised resistance to joining the alliance.

Some grumbling by diplomats from Russia, Bulgaria's old ally, has been noted, but has not caused significant debate.

An increased risk of terrorism is also sometimes mentioned.

In neighbouring Romania, Nato membership is supported by the vast majority of the population.

The country has been behaving like a member for some time, especially by providing air bases and naval facilities.

The ruling Socialist Party in Romania, like the opposition Socialists in Bulgaria, is fully committed to membership.

The only doubts being raised concern just why the south-east Europeans might be useful to the alliance.

The answer appears increasingly to be as a source of soldiers for peacekeeping operations in countries like Iraq and Afghanistan and for military training facilities in sparsely populated areas.