TO understand the weight and substance of Mikhail Gorbachev's announced intention to withdraw large Soviet forces from Eastern Europe, let us start with one essential fact. Since the end of World War II the Soviet Union has maintained in Eastern Europe an armored striking force superior in numbers of tanks to the combined tank strength of the NATO countries on the other side of the ``iron curtain.''
This is an ``offensive threat.'' It is both a military and a political force in being. Western Europe has been living with it and under its weight for nearly half a century. It is balanced off by the American nuclear deterrent. This balance of Soviet tanks versus American nuclear weapons has kept the peace in Europe since 1945, but peace on such a basis is indeed precarious. It is a poor substitute for a real peace. There will not be real peace with real security for Europe unless something better is put in place of this uneasy balance.
The first step toward such a real peace would have to be a removal of the threat of a massive Soviet invasion of Western Europe from East Germany. Is Mr. Gorbachev actually offering to remove that threat?
At the present time Moscow maintains a massive conventional force of men, tanks, and aircraft in forward positions in Eastern Europe, mostly in East Germany. In East Germany, Poland, Hungary, and Czechoslovakia combined, that force is made up of 16 armored divisions and 14 motor rifle divisions supported by 36 regiments of ground attack planes plus 18 regiments of fighter planes. Each regiment contains three squadrons of 8 to 10 (a variable) planes each. He says he is planning to remove 6 tank divisions, 5,000 of the tanks, and 50,000 of the men, out of a total of about 500,000 men.
This by itself would reduce the ``threat.'' It could even remove the ``threat'' if the forces sent home included the best tanks, the best-trained units, the best and most modern of the aircraft. We cannot judge the full weight of his proposed force reductions in Eastern Europe until we know precisely which units and which tanks and which planes he is sending back to the USSR, and also, how far back?
If all of these forces were merely to be pulled just behind the Soviet frontier, whence they could move back quickly into forward areas, the meaning would be in propaganda terms, not in military terms.
But if the best weapons and best units are pulled back home and disbanded and the weapons destroyed, it would make a large difference in the order of battle of the two sides in Europe.
No one expects Gorbachev to remove all his forces from Eastern Europe. But the announcement he made in his speech at the United Nations last week is certainly a welcome step in the right direction. He has not yet given up the ability to send his 30 divisions of tanks and armored personnel carriers surging over the North German plain. Few military people doubt that it could plunge toward and probably reach the Rhine in fairly short order.
Its ability to do that would certainly be reduced by his proposed force withdrawals. This might mean that his diplomats could go to a new conference on reduction of conventional weapons from a realistic base. His proposals, if tailored to that end, would mean that negotiations could start at a basis of parity.
Perhaps the most important thing he has done is to open the way toward a new round of talks on conventional weapons. He seems to be saying that he is ready to negotiate a real peace with the West, to be based on mutual and balanced security, instead of on that old uneasy and unstable balance of his offensive tanks in East Germany against American nuclear power.
May events prove this to be the case.