While weapons experts differ widely on how likely that scenario is, many have told New Scientist that they are extremely concerned about the state of India and Pakistan's nuclear arsenals, which lack many of the safeguards put in place by more established nuclear powers. They say it is too easy for rogue or misinformed commanders to unleash a nuclear missile or bomber. What's more, a warhead could detonate by accident, making its owner think it had been bombed, and triggering a counterstrike.
India is thought to possess some 35 warheads, and Pakistan between 24 and 48. Both countries claim to keep the warheads "disassembled", with the conventional explosive that initiates the chain reaction stored elsewhere from the nuclear material.
The risk of an accidental detonation depends on how readily the warheads can be reassembled. The Pugwash organisation, which campaigns for nuclear disarmament, quotes Pakistani generals as saying late last year that their warheads can be put together "very quickly", and have no "permissive action links", a security mechanism designed to prevent unauthorised access. The same seems likely to be the case in India.
But aside from fears about unauthorised attacks, simply moving warheads around or loading them onto aircraft or missiles can be risky. Geoff Forden of the Security Studies programme at Massachusetts Institute of Technology notes that the US had to perform many tests on its conventional explosives before it arrived at nuclear warhead designs that would not go off if some of the explosive accidentally ignited. But neither India nor Pakistan has done any such testing. "An accidental explosion would leave little evidence that it was accidental," says Forden. "The government would naturally assume it had been attacked, and retaliate."
American satellites that monitor launches could in theory reassure the aggrieved side that there had been no missile attack. But experts wonder if their advice would be believed, even if it came in time to avert a counterstrike. A joint US-Russian centre for providing such information, which was due to open in May, would add credibility to any reassurance. But it is not yet up and running.
There's no question that accidents do happen. Warheads in the US and the Soviet Union have been engulfed by devastating fires and explosions, though none has ever fully detonated. But M. V. Ramana of Princeton University in New Jersey notes that even if the very sensitive conventional explosives used in Indian and Pakistani warheads blew up without causing a chain reaction, the explosion would contaminate a large area with nuclear material and could cause thousands of cancers.
If there were a full nuclear explosion, it could also trigger events that might lead to a wider war, with China, the US and others rushing to support their allies after the supposed attack.
Author: Debora MacKenzie
New Scientist issue: 15 JUNE 2002
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