Russia's attack disproportionate

The reverse is also true. In the mid-1960's the Soviet Union has vehicles able to deliver up to six hundred or seven hundred nuclear warheads on the United States and perhaps seven hundred or eight hundred on our European allies. Their warheads are larger than ours (with up to 100-megaton ICBM's, while our largest are 9 MT).

In spite of the fact that their missile sites arc poorly organized, with missiles, fuel, crews, and warheads widely scattered, so that they arc at least twelve hours from takeoff even in their fourtl1 stage of readiness, the inaccuracy of our counter-force missiles is so great that we could not eliminate all their missiles, even if we made a first strike with no warning.

It would require only about 200 Soviet warheads to devastate our cities totally, and an American strike at Soviet missile bases delivered without warning would leave almost that number not eliminated; these would be free to make a retaliatory strike at us. Moreover, the Soviets have several dozen Polaris-type submarines that can fire four missiles each from surfaced positions. Many of these would survive an American unannounced first strike.

All this means that we are as much deterred by the Soviet missile threat as they must be by our much greater threat.

Such deterrence has nothing to do with the relative size of the numbers of missiles possessed by two countries.

It rests on whether an unannounced first strike would leave surviving enough missiles for a retaliatory strike capable of inflicting unacceptable damage.

This is now the situation on both sides, and the existence of Polaris-type missiles makes it impossible to avoid this by striving for greater numbers of missiles, for larger warheads able to obliterate wide areas, or for greater accuracy that would increase the statistical possibility of eliminating enemy missiles on first strike.

Thus no one will wish to make such a strike. Possibly for this reason, about a year after the Cuban missile crisis, the Soviet Union ceased to work on new missile bases and accepted its permanent inferiority to the United States. But the mutual veto on the use of missiles, the nuclear stalemate, remained.

This stalemate between the two Superpowers on the use of nuclear weapons also extended to their use of lesser, non-nuclear, weapons, so that the nuclear stalemate became a Superpower stalemate.

This meant that much of the power of the Soviet Union and the United States, and not merely their nuclear po\ver, was neutralized to a considerable degree, since each feared to use its non-nuclear powers for fear they might escalate into nuclear conflict.

This meant that the use of nuclear tactical weapons and the use even of conventional tactical weapons were inhibited to an undetermined degree by the presence of nuclear strategic weapons no one wanted to see used.

The costs of using nuclear tactical weapons are so great that it is very doubtful if they are worth the cost. For example, the Western Powers lack the conventional forces to stop any intrusion of the great masses of Soviet ground forces if these began to drive westward in an attempt to conquer Germany. The West is committed to oppose such an effort.

Since it is very doubtful that the NATO forces could oppose this successfully by using only conventional weapons, there would be great pressure to use the nuclear tactical weapons that NATO forces in Europe possess.

It has been estimated that the chief targets of such nuclear tactical weapons would be bridges and similar narrow passages, in an effort to close these to Soviet advances. But it seems clear that if these passages were closed and the bridges destroyed, the advance of the Soviet armies (in armored and mechanized divisions) would be held up only a few weeks at most, and up to so million Germans would be killed from the blast and side effects of the use of nuclear weapons. At such a cost, the Germans would probably prefer not to be defended...

http://real-world-news.org/bk

If USA builds the missile defense shield in europe, it will destroy the nuclear stalemate and alter the balance of military power in favour of USA. 

That is why Russia opposes it.