Soviet leader Mikhail Gorbachev's reform-minded policies are shaking the Western alliance as never before. ``Many of the certainties of the last 30 years are changing,'' says a senior United States official assigned to NATO. The question now is whether the West will be able to respond with a single voice. This is a concern echoed by many allied officials on the eve of the superpower summit set to begin Sunday in Moscow.
NATO defense ministers, meeting here this week to discuss a range of alliance issues, have worked hard to avoid overt signs of disharmony. But it hasn't been easy. NATO unity has been battered by a series of troubling events:
Denmark's indecisive vote earlier this month over whether to allow nuclear-armed ships into its harbors, leaving open the question of that nation's commitment to the alliance.
Spain's decision last January to force out a group of US F-16 fighters. The planes will now be moved to Italy.
Canada's announcement that it would no longer honor an agreement to reinforce northern Norway - citing a Norwegian policy that forbids the stationing of foreign troops in that country during peacetime. The Canadians argue that the provision makes a joint defense effort unworkable.
NATO observers say these moves underscore a growing ambivalence on the part of some Europeans toward integrated defense efforts.
``The key problem for NATO right now,'' says a British defense official, ``is convincing our publics that there is still a threat from the East in raw military power.'' And this is becoming increasingly difficult, he adds, ``in the face of this new Mr. Gorbachev - a smiling Russian leader.''
On one hand, the allies are eager to see the Soviet Union lower its guns, if only slightly. The Soviet pullout from Afghanistan, together with the historic agreement between Washington and Moscow to do away with land-based intermediate-range nuclear missiles, are widely seen in Europe as evidence of a new era in East-West relations.
But many worry that Soviet overtures toward the West could cause long-term security problems - if they are not accompanied by corresponding reductions in conventional arms.
The Warsaw Pact holds a hefty edge over NATO in both tanks and troops. More importantly, say NATO officials, the East bloc has yet to alter the structure of its forces, which is considered threatening to the West.
This continuing imbalance has also given special impetus to the latest allied dispute over ``burden-sharing.''
The removal of intermediate-range nuclear forces will make Western conventional forces all the more important - since the nuclear weapons to be removed have been used to counter conventional as well as nuclear forces.
Congress is pushing hard for evidence that US allies in Europe are willing to shoulder a bigger chunk of the cost for regional defense.
Deputy Defense Secretary William Taft, who heads a special task force on burden-sharing at the Pentagon, took this message with him on a tour of European and Asian capitals earlier this month.
On Tuesday, he reported back to a House panel that he was pleased with how quickly the allies have moved to take up the issue.
Burden-sharing dominated the agenda at this week's defense ministers' meeting, where officials sought to smooth over the differences as much as possible.
The ministers agreed to launch a special burden-sharing study which would directly address the concerns of Congress. The study is scheduled to be released in December, after the US election - a crucial time for influencing Capitol Hill as well as the incoming administration.