NATO plans to approve by next spring an overhauled strategy that dramatically reduces the number of nuclear weapons and size of standing conventional forces in Europe, allied defense ministers said Friday.

The defense ministers, concluding a two-day meeting of NATO's Defense Planning Committee and Nuclear Planning Group, said the alliance must adapt to the past year's stunning changes in Europe."The risks the allies now face in Europe arise principally not from the likelihood of deliberate aggression against allied territory, but rather as unforeseeable consequences of instabilities that might emerge in a period of rapid and widespread political, social and economic transformation," they said in a final communique.

NATO's new force structure, the defense ministers said, must be able to respond quickly to localized conflicts in Europe.

"Our future force posture will be based on smaller, more mobile and flexible active forces," many of them comprised of multinational units, they said.

There will also be "further dramatic reductions in the number of NATO's nuclear weapons retained in Europe," the NATO ministers said.

NATO strategy for decades was based on the now-obsolete policies of "forward defense" and "flexible response," which called for the use of nuclear weapons if necessary to repel an overwhelming conventional attack.

Those policies, said NATO Secretary-General Manfred Woerner, have "been largely overtaken by events," including the signing last month of a massive conventional arms treaty that eliminates risk of a surprise attack in Europe.