During the later phases of the Vietnam war the people of the United States became increasingly aware of limits on the use of their physical power. They had superior physical power over their opponents in Vietnam. But it did not bring them a decisive military victory in Vietnam. Why?
One of the more interesting features of the present world situation is that such a question is being asked now about Soviet military power. We hear daily about how great that physical power is. It is very great indeed, and it continues to increase. Yet it has not brought Moscow a decisive victory over the stiff-necked Afghan tribesmen in spite of a year of bombing and gunning and killing.
The raw exists in Soviet hands to wipe out dissent against the Soviet system in Poland. Indeed, Moscow could wipe Poland off the map, physically. Yet Moscow has hesitated to use this raw power against Poland.Why?
In both the case of the US in Vietnam and of the Soviets in Central Europe the answer is the same. The use of raw power, like the use of drugs, tends to have side effects. Sometimes those "side effects" are worse than the condition being treated.
The US had the physical power to invade North Vietnam and reach for the Chinese frontier, but when precisely that was done in Korea, the Chinese came down to meet the Americans and won a decisive victory. The US could have retaliated by bombing across the Yalu, as General MacArthur proposed, but that would have led to a war between the US and China and might have brought the Soviet Union in. Was it worth fighting a general war against China and perhaps the Soviet Union as well just to consolidate the US hold on North Korea? The answer was no. The possible cost outweighed the possible gain.
Suppose that the US had chosen in Vietnam to reach for the Chinese frontier, and then found itself for a second time fighting the Chinese. A certain consequence would have been to delay the breach between China and the Soviet Union which is today one of Washington's most important assets in world affairs. Merely to have Peking at odds with Moscow is worth roughly a million soldiers, because it ties down that number of Soviet troops along the Chinese border.
In terms of relative military power the US is substantially stronger today because it has abandoned the policy of deploying major forces against China. From 1950 to 1972 the US kept enough military power in the Far East to threaten China. That in turn forced the Chinese to man their eastern frontier with enough force to neutralize that threat, thus reducing their potential deployment against the Soviets.
When Washington abandoned the policy of hostility toward China the world strategic situation was transformed. The Chinese, no longer fearing a possible US attack on their borders, could concentrate all their strength against the Soviets. The Soviets had to increase their deployment along the Chinese frontier. The US had all its strength available for other parts of the world.
This strategic condition still prevails. Now it is Moscow which feels the limits on the use of its power. It could undoubtedly wage a "preventive" war against China and take out China's nuclear capability, but several Soviet cities would probably be destroyed by Chinese nuclear bombs in the process. It could mean the destruction of the economy of the Soviet maritime provinces. Would the operation be worth that price?
The price would also include further weakening of communism as a Soviet instrument of influence, already gravely weakened by the repression of independence in Hungary and Czechoslovakia. Another use of Soviet power against a communist country would probably mean the end of any semblance of world communism.
Even limited use of Soviet power inside Poland could do damage equal to the possible gain. It would so alarm West Europeans that they certainly would cut down on their trade with the Soviet Union and its client states. And that would damage the economies of those countries. The Soviet economy is already dangerously sluggish. The loss of modern machinery imports from the West could outweigh in long-term effects the possible gain.
Some Western experts say that Soviet military power now exceeds that of the US. But that very condition is one of the limits on it. It scares off countries which might otherwise become friendly.