Brussels — A NATO reevaluation of the Warsaw Pact shows fewer forces ready for combat on a European front. This update of a 1982 force comparison still claims the Warsaw Pact maintains forces ''well in excess of that reasonably justifiable for defense.''
But the result is a much closer military balance in Europe and more favorable situation for the Western alliance which is geared for a defensive conflict. Military doctrine holds that an attacker needs at least a 2-to-1 or even 3-to-1 edge over defensive formations to win.
The reason for the change is that past assessments of Warsaw Pact strength have included all Soviet and Warsaw Pact forces facing NATO from Norway to Turkey, totaling some 173 divisions.
The revised estimate excludes those Warsaw Pact forces that are not combat-ready or that are too far away in the Soviet Union to be immediately useable. Thus, under the new calculation, only some 115 Warsaw Pact divisions would face about 88 active and mobilizable NATO divisions.
Outgoing NATO Secretary-General Joseph Luns, in his farewell press conference with the Netherlands' Gen. Cornelius de Jaeger, chairman of the NATO military committee, added that French and Spanish forces, which were not included in this East-West comparison, would add about 10 percent to that NATO capability in a conflict. (France and Spain are not in NATO's military structure).
They called the new evaluation more ''realistic'' than in the past.
Dr. Luns also expressed satisfaction with the US Senate's rejection of an amendment to the defense authorization bill that could have led to reductions of some 100,000 American troops in Europe unless European allies spent more on defense.
He said adoption would have been ''deplorable'' and would have ''demoralized'' Europe.