IT IS ONE of the many additives of the nuclear age that while many nations depend on nuclear weapons for their security nobody really knows how much damage those weapons would actually wreak in the event of nuclear war. Though nuclear weapons tests have been conducted since the dawn of the nuclear era history offers us only two instances of military use the atomic bombings of Hiroshima and Nagasaki.
Generally, we are thankful for the scarcity of data. Most civilian and military strategists agree that a large scale nuclear attack launched against either the U.S. or the U.S.S.R. would devastate the victim nation killing as many as a hundred million people and crippling the national economy. Haunted by the specter of such destruction governments in both nations pursue policies that they believe will minimize the likelihood of all out nuclear conflict though debate rages on the methods there is a consensus as to the common goals.
But while perceptions of the horrors of nuclear war have shaped out long term nuclear objectives considerations about concrete probable effects of nuclear war have not entered into the formulation of strategic doctrine. This approach is a tragically misguided one for as two studies published recently indicate the actual long term consequences of nuclear war would prove far worse than have been previously imagined. If we are to develop a meaningful nuclear war doctrine, U.S. policy makers must adopt strategies which acknowledge the true capabilities of the world's nuclear arsenals.
R.P. Turco, O.B. Toon, T.P. Ackerman, J.B. Pollack and Carl Sagan in a study entitled "Nuclear Winter Global Consequences of Multiple Nuclear Explosions" (and referred to as TTAPS after the authors names), examine a previously ignored effect of nuclear detonations: the creation of dust and soot that can float in the middle and upper atmosphere for years. Isolated detonations the only kind we have witnessed in our experience with nuclear weapons to date do not generate enough dust and soot to create any long term atmospheric changes. But any nuclear war between the superpowers is likely to involve thousands of warheads launched within hours certainly no more than days of each other. Such massive detonations would create enough dust to block the sun's light entailing catastrophic global consequences.
A GLOBAL NUCLEAR WAR, the study concludes would have extreme consequences for the global climate creating surface darkening over many weeks subfreezing land temperatures persisting for up to several months and strong monsoon like weather patterns. In short the study notes "a harsh 'nuclear winter' in any season."
In a related study on the "Long-Term Biological Consequences of Nuclear War," 20 biologists headed by Paul R. Erlich examine what will become of life on earth during such a nuclear winter. Freezing temperatures would kill many plants; the gloomy darkness would make it impossible for surviving vegetation to undergo photosynthesis Agriculture would suffer irreparable damage and global food chains would be hopelessly shattered. Increased radiation would prove lethal to plants, marine life and land mammals. The overall repercussions would "lead to the extinction of the species of plants, animals, and microorganisms of the Earth," the study contends.
And should humanity survive the initial shock of nuclear winter the study concludes the long term outlook remains pessimistic.
It is clear that the ecosystem effects alone resulting from a large scale thermonuclear war could be enough to destroy the current civilization in at least the Northern Hemisphere. Coupled with the direct casualties the combined intermediate and long term effects on nuclear war suggest that there might be no survivors in the Northern Hemisphere the possibility of the extinction of Human suspense cannot be excluded.
NUCLEAR WAR, the TTAPS study tells us offers far more devastation than we had ever imagined. But those who accept the study's findings and who then fail to re-evaluate current strategic postures, have missed the point. The prospect of nuclear winter contains significant implications for nuclear strategy.
First, the TTAPS findings should dampen the historic emphasis on developing ever more survivable nuclear forces. Though each of the superpowers has in absolute numbers weapons sufficient to destroy the other several times over strategists usually focus instead on the projected post strike balance. How much will be left in each side's arsenal after it has been attacked? Would that stockpile be sufficient to coerce of deter the other side's behavior? Emphasis on post strike balance implies for instance that the U.S. can secure deterrence only by maintaining an arsenal so large that even after a Soviet first strike enough U.S. forces would survive to launch a devastating retaliatory strike. The result has been the arms race; each side views the other's new weapons as a threat to the size of its survivable force and counters with a weapons system of its own.
But the TTAPS findings make survivability and retaliation unnecessary. A first strike attack even one directed at just military targets, would cause enough of a nuclear winter to "wipe out all the grain growing regions of the United states, Canada and the Soviet Union." A nation launching a first strike will effectively commit suicide regardless of the adversary's response. As Sagan put it in a recent lecture at the Kennedy School, "the attacked nation need not lift a finger for retribution swift and final to fall on the aggressor."
The prospects of a nuclear winter also should affect thinking about extended deterrence the dependence on U.S. intermediate and intercontinental nuclear forces to prevent a Soviet invasion of Western Europe. A nuclear winter implies that the U.S. cannot credibly extend its nuclear umbrella since like a first strike a nuclear attack in response to a conventional assault is certain suicide.
But the study does suggest an alternate strategy for deterring a Soviet invasion of Europe. While the threshold beyond which nuclear detonations will create a drastic "nuclear winter" is quite low it does not preclude the use of small battlefield nuclear weapons. The U.S. could use such small yield weapons to offset any real or perceived conventional asymmetry Presumably neither side would risk approaching the threshold by escalating the conflict to include medium range or strategic forces.
By targeting only battlefields. NATO can credibly threaten to employ tactical nuclear weapons in response to a Soviet conventional thrust into Europe. In view of the TTAPS findings the risk of rapid escalation of forces to an all out exchange virtually disappears. So deployment of large warheads not the quick introduction of small ones is what the U.S. must avoid in any European confrontation. By shying away from No First Use pledges the U.S. can discourage any Soviet adventures in Europe without spending billions of dollars to beef up NATO's conventional forces.
SOME ARGUE, rightfully that the Soviets must also come to understand the implications of a nuclear winter before the U.S. can revise its strategic posture. Some deny that the Soviets will ever do so. The TTAPS findings do require more study before strategists either here or in the U.S.S.R., accept them as fact. Once confirmed, however it is reasonable to think the Soviets will accept the prospect of the nuclear winter. The arms race itself is testimony that scientific truths know no national borders.