Following the controversy on the success or otherwise of the thermonuclear test of India on 11th May, 1998, questions have been raised by some senior ex-service officers and civilian strategists on the credibility of the Indian deterrent posture and the perceived mismatch between a 3,500-km missile and a warhead of two digit explosive yield. It is not the intention here to go into the question of success or otherwise of the thermonuclear test. Heaven knows so much has been said about that already. Instead, there is a need to understand what we mean by deterrence and we shall also discuss whether Indian nuclear strategic posture is credible in the absence of thermonuclear warheads.
Nuclear deterrence is essentially a mind game. A potential aggressor will be deterred if he is persuaded that the nuclear retaliation that will be delivered by the survivable nuclear force of the victim will cause unacceptable damage, totally incommensurate with any strategic, political, economic or any other objective that drives him to go for the first strike. During the Cold War, the Western assumption was that Communist ideological expansionism constituted a threat to the very survival of democratic system. But as George Kennan pointed out, the Communists while espousing an offensive ideology were also convinced that history was on their side and were not ready to push it at the risk of a nuclear conflict. Both sides thus opted for a status-quo and the world was spared a nuclear war.
In the sixties the U.S. gave serious thought to the possibility of carrying out a total disarming strike on the Soviet Union when it had more than ten times the superiority in warheads. The U.S. Chiefs of Staff could not, however, assure the President that a few Soviet warheads would not get through to the U.S. and that was enough to deter Washington from pursuing that idea of a disarming strike.
No doubt Robert McNamara as Defence Secretary came up with very fanciful calculations of what percentages of Soviet population and industry should be threatened by assured destruction to become the deterrent. These calculations were based on the Soviet Union suffering 20 million casualties in the Second World War and enormous damage to its industry in the European part of Russia. But that happened incrementally over four years of the war and the Soviet leadership could not have known there would be such losses when the Nazi aggression took place. In real world, the Soviets could not accept the loss of fifteen thousand lives in Afghanistan and pulled out of that country. In a sense, the U.S. calculations were a misplaced justification to build an arsenal of several thousand warheads and engage the Soviet Union in an arms race. Having built 30,000 warheads at great costs, both sides are now cutting back on their arsenals and dismantling those weapons, again at great cost.
Robert McNamara in later years of his life changed his views. Writing in Foreign Policy of May/June 2005 he said that he had never seen any U.S. or NATO war plan which concluded that initiating the use of nuclear weapons would yield U.S. or the Alliance any benefit. He added that his statements to this effect had never been refuted by any NATO Defence Minister or senior military leaders. Yet it was impossible for any of them, including the U.S. Presidents, to make such statements publicly because they were totally contrary to established NATO policy
War is politics by other means and the aim of a war is to compel the adversary to accept one’s terms. President Reagan and the Soviet Union’s General Secretary Gorbachev are on record that a nuclear war cannot be won. In a nuclear war, once the missiles are launched, entire countries on both sides become battlefields. It is difficult to control or regulate the firing of the missiles since both sides are under compulsion to use the missiles before they are eliminated by the enemy strike. As soon as the first city is hit, populations of all cities would attempt to empty out into the countryside since there will be panic that their own city will be the next target in the next few minutes. Think of the entire urban population of a country becoming internally displaced persons in a matter of hours. Can there be effective governance in the country?
A thermonuclear weapon of 150 kiloton explosive power or three 25 kiloton warheads delivered in a distributed way on a city will perhaps produce equal magnitudes of casualties and property damage. Can it be argued that only a 150 kiloton weapon will deter another warhead of a similar yield? Deterrence is not about the damage one causes to the adversary. It is about what the aggressive side will consider as unacceptable. It is irrelevant whether the destruction is caused by 150 kt weapons or 25 kt weapons. Obviously, it is not infra-dig for a 3,500-km range missile to carry a 25 kt warhead. Cost-effectiveness calculations have no meaning since the nuclear war itself has no meaning. In a mega-city struck by a couple of 25 kt warheads, apart from the hundreds of thousands of dead, there will be an equal number of people wounded and more people affected by radiation; all of whom will be envying the dead. One of us is revisiting the calculations involved in predicting the extent of destruction inflicted by nuclear weapons. Our preliminary results suggest that that even with 25kt fission bombs, the damages are going to be far more and extensive than what Hiroshima and Nagasaki suffered given the higher population densities in the cities of China and South Asia and the urban development of recent years. Therefore, the Indian deterrent posture will not lose its credibility if India is compelled to rely on fission weapons only.
The role of the Indian nuclear weapons is to deter others using nuclear weapons against us. It can perform that role so long as the retaliatory force is perceived as survivable and able to inflict unacceptable damage on the aggressor. That does not depend on the explosive yield of the individual warheads. Theoretically speaking, the same unacceptable damage can be inflicted by increasing the number of delivery vehicles and warheads of lower yield and increasing their survivability. Reliability, robustness and survivability of weapon platforms are important determinants in validating the deterrence a country practices.
In this article we do not propose to sermonise on the need to eliminate nuclear weapons globally. This was articulated by Rajiv Gandhi in the United Nations many years ago, but has not been pursued since then. Along with our deterrence policy, we should once again pursue the mission for the global elimination of nuclear weapons. Our world will be better for that and fission or fusion will then lose their relevance.
( K. Subrahmanyam is a well known strategic analyst and V.S. Arunachalam, a former Scientific Advisor to Defence Minister, is now Chairman of CSTEP, a Bangalore-based think-tank.)