In a historic eastward shift, NATO expanded its membership beyond the borders of the former Soviet Union on Thursday amid a makeover designed to answer new threats of global terrorism.
The Western alliance — which for decades confronted the U.S.S.R. across the barbed-wire divides of Central Europe — invited seven former communist countries under its security umbrella as part of reforms that President Bush called the most significant in NATO's 53-year history.
Barely a decade since they regained independence from the Soviet Union, the Baltic nations of Latvia, Estonia and Lithuania joined Bulgaria, Romania, Slovakia and Slovenia in receiving a call to become NATO members at the alliance's first summit behind the old Iron Curtain.
"By welcoming seven members," Bush said, "we will not only add to our military capabilities, we will refresh the spirit of this great democratic alliance. We believe today's decision reaffirms our commitment to freedom and our commitment to Europe which is whole and free and at peace."
NATO Secretary-General Lord Robertson said the summit was "a truly defining moment for the Atlantic Alliance. We will reinforce that essential trans-Atlantic bond on which our security and defense still depends. We have the organization, the military capabilities and the will to deal with threats to our people wherever and whenever they may come."
The seven new countries will formally join the alliance in May 2004 after the U.S. Senate and the parliaments of the NATO member countries ratify the expansion.
Speaking to students in the Czech capital on the eve of Thursday's summit, Bush said the new members would reinvigorate an alliance seeking to transform itself into a force to fight the dangers of terrorism and renegade governments armed with weapons of mass destruction rather than the threat of Cold War-era tank assaults.
"Those with fresh memories of tyranny know the value of freedom," Bush said Wednesday. "In Central and Eastern Europe, the courage and moral vision of prisoners and exiles and priests and playwrights caused tyrants to fall ... this spirit is needed in the councils of a new Europe."
French President Jacques Chirac took up the theme, telling Czech television the NATO expansion — to be followed next month by a European Union decision to invite in eight former communist nations — was "an affirmation that there can be no more splits in Europe."
As well as extending NATO's territory into the Balkans, Baltic states and Central Europe, leaders will approve an overhaul of the way the alliance does business and try to silence critics who say it has drifted into irrelevance in the post-Warsaw Pact, post-Sept. 11 world.
Among the decisions before the summit was one to pool crack troops in a 20,000-strong rapid-response force to tackle threats anywhere around the world, burying NATO's old reluctance to act outside its established European and North Atlantic spheres of influence.
European allies also will pledge to beef up their outdated militaries with smart bombs, anti-germ warfare gear and heavy-lift planes to get troops and equipment to trouble spots quickly. NATO will also streamline its command structure under a U.S. general in a new post as strategic operational commander.
The aim is to give the alliance the flexibility to respond immediately to today's unpredictable dangers and close the gap between America's military might and European armies weakened by years of defense cuts.
"NATO has the strength and flexibility to defy its critics and to change, to undertake the tasks we all need in a complex and dangerous security environment," Robertson said Wednesday in a pre-summit address.
Bush stressed that the new NATO members will have to pull their own weight in the alliance like the Poles, Hungarians and Czechs who joined in 1999 as the first ex-communist members. But once in, they will enjoy the protection of the all-for-one, one-for-all security guarantees that come with membership.
"Anyone who would choose you for an enemy also chooses us for an enemy," Bush said. "Never again in the face of aggression will you stand alone."
Bush's speech was a strong affirmation of U.S. support for NATO, whose future was questioned by critics in the United States after Washington declined to seek its support during the war against Al Qaeda and the Taliban in Afghanistan last year.
Those same critics are now looking intently at the role — if any — that the alliance might play if the United States goes to battle against Iraq. Although NATO is expected to issue a message of support for the U.N. weapons inspectors' mission to Iraq, Bush indicated the United States would be looking for a "coalition of the willing" for military support rather than turning to the alliance as a whole.