Over the last two decades, two broad views of the future in the nuclear age have been contending in American strategic thought. Both views recognize that our own defense effort must be complemented by internationally agreed policies that will restrain and reduce the nuclear arsenals.

But if peace is to be preserved, according to the first view, mankind must remain locked into permanent hostile confrontation of missile forces poised for instant retaliation. The second view searches for ways to stop a nuclear attack, rather than relying exclusively on the threat of revenge, and seeks to harness science and technology to reduce the role of nuclear arms. In the 1970s, the first view largely dominated our strategic policy.

The first view is like a permanent nightmare; the second view is a vision of the future that offers hope.

According to the first view, we must, for the indefinite future, rely on strategic forces that can revenge a missile attack but not defend against it, on weapons that can destroy cities but cannot protect them, on forces forever poised to avenge but never to save lives.

This view implicitly accepts a world of nations frozen into an evil symmetry: two "superpowers" forever confronting each other with hair-triggered missile arsenals, leashed precariously by the fear of "each side" that its society is threatened by devastating nuclear retaliation. This view of the world imagines that the U.S. and Soviet governments act alike. Indeed, it is the hallmark of this strategic philosophy that "they" and "we" are always interchangeable. If the United States has some legitimate fears about Soviet military policies, "they" must have exactly symmetric fears about us. If we base our defense on a need to deter Soviet military aggression, "they" must be driven by a symmetric objective. Moreover, there is no room in this simplistic view for the fact that more than "two sides" control nuclear weapons, and more nations will yet acquire them. And little allowance is made for the risk of accident and irrational acts.

If we continued to follow this nightmare view of the nuclear age, arms control would hit a dead end. Since "each side" in this view must retain offensive forces able to ensure nuclear revenge, reductions in missile arsenals at some point become destabilizing. Indeed, some people of this persuasion have criticized the arms reductions proposed by President Reagan as endangering the stability of the "mutual" deterrent relationship. If nuclear weapons must remain forever invincible, then arms control could never lead to low levels of nuclear offensive arms since, in a world without defenses, a few hidden weapons could mean a decisive military advantage.

Worse yet, according to some proponents of this nightmare view of the world, arms policy must rig our strategic forces so that they could only be used to kill civilians, not to destroy military targets. Consonant with this attitude is the belief that outer space, rather than the cities we live in, ought to be protected from military competition. Thus, the president's decision to pursue defenses against ballistic missiles is being criticized as "militarizing" outer space. What are the priorities of those who eschew possibilities for increasing the security of the space we live in, just so as to preserve some pristine sanctuary in outer space?

The president's decision to remove the doctrinal blinders against strategic defenses cannot overcome our current predicament overnight. But it offers a new hope. To travel the road now being unblocked will call for much careful choice and thoughtful change. Research and development priorities will have to be pursued; and as we realize the vision of a different and safer strategy, we must continue to include our allies in this development.

The scope and opportunities have now been widened for arms control negotiations that can grapple with the fundamentals. There is evidence to suggest that over time the Soviet Union will become receptive to such a new approach. Sixteen years ago, at a U.S.-Soviet summit meeting in Glassboro, N.J., President Johnson argued that arms control negotiations should give top priority to curbing systems that could defend each country against ballistic missiles. The Soviets disagreed: "I believe," Kosygin explained, "that defensive systems, which prevent attack, are not the cause of the arms race, but constitute a factor preventing the death of people."

The nightmare view of the nuclear age has broader implications, going well beyond the question of missile defenses. It becomes an excuse for not improving our conventional defenses, for a reckless reliance on nuclear escalation: "Any major war will 'go nuclear,' any use of a nuclear weapon will mean global holocaust, so why spend more money on conventional forces?" It is symptomatic of the incoherence of the nightmare strategists that they usually hold three incompatible positions: that we can safely cut our conventional defense budget, that we can safely rely on the threat of nuclear escalation, that any use of nuclear arms will mean the end of the world.

The Reagan administration has emphasized conventional force improvement, precisely to reduce our reliance on the threat of nuclear escalation. "We must take steps," President Reagan said Wednesday night, "to reduce the risk of a conventional military conflict escalating to nuclear war by improving our non-nuclear capabilities. America does possess--now--the technologies to attain very significant improvements in the effectiveness of our conventional, non-nuclear forces."

Given congressional support for the president's defense budget, we can improve and deploy conventional forces that would be effective. Such forces could discriminatingly repel an attack-- without destroying ourselves or our allies. In this way, and in this way only, will we have an effective deterrent to conventional aggression.

As the president stressed, we face a formidable task and there will be failures and setbacks. But we can count on the common sense of the American people to reject the permanent nightmare and support the vision that offers hope.(FOOTNOTE)red C. Ikle; The writer is undersecretary of defense for policy. (END FOOT)