New Delhi: In the realm of nuclear deterrence, anti-ballistic missiles occupy a rare place. Simple men with strong conservative views cannot accept the intrinsic cynicism of deterrence theory based on the balance of terror. Deterrence theory argues that deterrence is achieved when nuclear adversaries have the equal capacity to annihilate one another and recognize this. It imposes a manner of rationality on leaderships controlling and commanding nuclear weapons to never use them since it would invite their own destruction and that of their people and civilization.

Simple men like Ronald Reagan were appalled by the danger of miscalculation inherent in deterrence theory. Thousands of American and Soviet nuclear weapons posed an unimaginable magnitude of danger to each others’ population and there was no escape from the nightmare. When strategists by and large expressed helplessness to remedy matters, Reagan was appalled. When a military briefing gave him the idea of strategic defence, he pounced on it. The rest of his presidency was devoted to the strategic defence initiative and neither the Soviets nor his advisers could dissuade Reagan about its unfeasibility. It took another simpleminded president, George W. Bush, to finally scrap the ABM treaty with the Soviet Union. New R & D on ABMs ordered by Bush led to the development of such missiles as THAAD but they haven’t been able to overcome deterrence theory. The balance of terror remains the best formula to deter nuclear war.

Governments aren’t done with developing anti-ballistic missile shields. India is attempting to build one. Success of an ABM to destroy its target is usually touted as proof of workability of a defence shield. Not so fast. Test conditions cannot replicate real-life scenarios. ICBMs, for example, are notoriously hard to track and destroy. It is most vulnerable in its first and second stages and requires defensive action in fractions of time that are virtually impossible to achieve. In its final stage, its very high velocity cannot guarantee interception.

Robert McNamara was among the earliest to visualize the dangers to deterrence posed by ABMs. He was clear it would lead to an arms race. If a country developed and deployed an ABM shield, its nuclear adversary would seek to overwhelm it with masses of offensive missiles in the hope that some would breach the defences. A shield is worthless if it is not 100 per cent foolproof.

Part of the reason for McNamara’s opposition to ABMs was that MIRVed ICBMs were on the horizon. He tried to dampen US enthusiasm for MIRVs because the Soviets lagged there saying problems would arise once the Soviets caught up. He enunciated a remarkable principle in the process cautioning not to trust in technological superiority forever.

The India-Pakistan nuclear dynamic is still rudimentary but there is merit in learning from the Cold War. There is no alternative to deterrence and the balance of terror. Research on ABMs is valuable because it advances understanding of rocketry. But strategic defence cannot be a substitute for strategic offence. The idea died with Ronald Reagan.

Strategic offence, however, could be made more responsible and predictable with arms control. As a nuclear confidence-building measure nothing compares to it. There is no movement in the two countries for arms control and this is a grave deficit between two rival nuclear powers sharing contentious frontiers. This writer cannot foresee arms control negotiations taking place between India and Pakistan in the foreseeable future. Relations have irremediably soured.

Nevertheless, arms control cannot be avoided for long. Nuclear weapons demand CBMs. They compel diplomacy. ABMs are a disruptive tool. They will lead to an arms race that neither India nor Pakistan can sustain. The success of ABMs in test conditions does not mean they will meet real life contingencies. In a majority of cases, they will not. So long nuclear weapons exist they will be governed by deterrence. Strategic defence is a mirage.