After World War II and during the ensuing Cold War, Sweden publicly maintained its neutrality and its government did not allow research or construction and testing of nuclear weapons. But, according the 1985 article, Sweden's did, in fact, pursue nuclear weapons research and development, led by an inner circle of politicians, scientists and members of the military under the guise of producing nuclear energy for peaceful purposes.

According to a winter 1998 article in the Nonproliferation Review on Sweden's nuclear history, the Swedish Defense Research Agency (FOA) began its research on a nuclear weapon in 1952. Two dual-purpose reactors, capable of producing electricity as well as nuclear weapons material, were built in the towns of Agesta in the 1950s and Markiven in the mid-'60s.

In 1968, Sweden signed the nuclear Non-Proliferation Treaty, but FOA continued its military research. Between 1971 and 1972 the military conducted 10 underground implosion tests using weapons-grade plutonium which, according to the Swedish Ministry of Defense, was imported from France and Britain. Although the tests were not nuclear explosions, meaning they did not release energy from the fissioning of atoms, the tests were the kind normally carried out in the final stages in preparation of exploding a nuclear bomb.

FOA abandoned plutonium testing in 1972, and in 1974 all plutonium facilities were disassembled and the FOA was reorganized, according to the Nonproliferation Review.

The Swedish Nuclear Power Inspectorate was established in 1976 to police nuclear activities in Sweden in conjunction with the government.

-- Compiled by Wendy Mbekelu for the Online NewsHour