SEOUL: North Korea’s quest for nuclear weapons has relied on the former Soviet Union, China and more recently a smuggling ring linked to the father of Pakistan’s own atom bomb.

The North has sought nuclear weapons since the end of the 1950-1953 Korean war, when Washington stationed nuclear warheads in South Korea and Japan.

Pyongyang then got help from the Soviet Union and China in launching its own drive to acquire the bomb. Later, assistance was obtained in crucial technology areas from other countries, including Pakistan.

In the mid-1950s North Korea signed a research agreement with Moscow under which hundreds of its scientists were trained in nuclear physics by the Soviets. Pyongyang later signed a similar cooperation agreement with China.

Around 1960, North Korean leader Kim Il-Sung ordered the construction of an atomic energy research complex in Yongbyon, 90 kilometres (55 miles) north of the capital, Pyongyang.

Two years later Soviet scientists helped the North Koreans assemble a two-megawatt IRT-200 research reactor shipped by Moscow to Pyongyang. In return, North Korea exported the spent fuel back to the Soviet Union. The reactor was in operation in 1965.

In 1974, North Korean leader Kim visited China, and reportedly won China’s promise to train more North Korean nuclear scientists.

North Korea was ready to step up its nuclear drive and five years later began work on a second reactor at Yongbyon. The five-megawatt research reactor was operational in 1987, and ready to produce some seven kilogrammes of plutonium a year, enough for one or two nuclear weapons.

At about the same time, the reactor was shut down and North Korea was suspected of unloading it and reprocessing spent nuclear fuel rods to separate around 12 kilogrammes of plutonium, enough for a couple of atomic bombs.

Washington accused North Korea of actively pursuing nuclear weapons.

Pyongyang denied the charge but started to build two larger reactors, a 50-megawatt and a 200-megawatt plant.

Finally the North declared in February 2005 that it had built nuclear weapons. The CIA has stated in the past that it believes Pyongyang has created several crude nuclear bombs.—AFP