Islamabad races to build secret nuclear arsenal

PAKISTAN could have up to half- a-dozen nuclear bombs - the minimum for an operational nuclear power, according to US intelligence sources. The first Muslim state to possess nuclear weapons, or with the undisputed ability to build them, has pursued two routes: uranium enrichment and the acquisition of plutonium. The bombs Pakistan probably possesses use uranium-235. But a plutonium reprocessing plant is under construction, so it makes sense for Pakistan to import plutonium.

In 1966 President Ali Bhutto said Pakistanis would 'eat grass', if necessary, to acquire nuclear weapons. India's explosion of a nuclear device in 1974 led to redoubled efforts to build a bomb with assistance from China. Plutonium weapons must be tested, unlike uranium ones.

Pakistan claims it does not possess nuclear devices, although it has admitted producing 'cores' for them. Islamabad denied yesterday that it was linked to a conspiracy to smuggle plutonium from Germany, as suggested by authorities in Berlin. They have not elaborated on a statement that police found evidence of a Pakistani connection during raids on seven apartments in the city.

In 1990 the then US President, George Bush, was for the first time unable to certify that Pakistan did not possess such a device. An amendment to the US Foreign Assistance Act, directed specifically at Pakistan, requires the president to certify each year that Pakistan does not have nuclear weapons before military or economic aid is authorised. A consignment of F-16 fighter planes, which Pakistan has paid for, is being held back until Pakistan can prove compliance with US conditions.

The centre of Pakistan's nuclear weapons programme has been the Kahuta uranium enrichment facility. It is estimated to produce between 20 and 38kg a year and has produced up to 200kg. About 25kg of uranium-235 are needed for a first-generation nuclear device. Plutonium bombs are more complicated to make but require much less nuclear material.

Pakistan has a Kanupp power- reactor outside Karachi, supplied by Canada, which is now subject to International Atomic Energy Agency safeguards. However, in the late 1970s and early 1980s the reactor, which is a perfect device for making weapons-grade plutonium, was not always subject to safeguards.

In the early 1980s Pakistani military journals discussed operating in a nuclear environment in a war against India. Pakistan was defeated by India in 1965 and 1971. The two nations nearly went to war over Kashmir in 1990. In February 1993 the Director of the CIA, James Wolsey, told the Senate Government Affairs Committee: 'The arms race between India and Pakistan poses perhaps the most probable prospect for future use of weapons of mass destruction, including nuclear weapons.'

The Pakistani nuclear programme has been pursued in great secrecy. In January the Prime Minister, Benazir Bhutto, banned public discussion of nuclear power plants. Any Pakistani nuclear weapons will be bombs for aircraft, as experts do not believe Pakistan can build missile warheads.

Its nuclear programme has been aided by China. But with the break-up of the Soviet Union, Pakistan would be an attractive destination for scientists from the southern republics.