Classified memos and reports, made public for the first time, show that, for 18 years after the Second World War, senior Swiss army commanders and scientists actively studied Switzerland's nuclear capability with government approval.
In 1946, a government- appointed commission was ordered to examine the feasibility of a Swiss bomb. By 1958, while the Swiss were completing a network of bomb shelters, the army told the government that "the deployment of an atomic bomb for our army . . . is urgently necessary . . . . We need the atomic bomb.''
Extracts from the documents, published in the Swiss press, indicate that the military considered that an atomic weapon could be used inside Switzerland against an invading force. Its potential as a deterrent was also mentioned. In 1957, at a meeting of the country's defence commission, which included the then defence minister, Paul Chaudon, leading army officers said they feared a Switzerland without the bomb would be considered "the number one target for the Russians" since it was "well-known as an anti-communist bastion within Europe". Yet during this period the government publicly repeated Switzerland's neutrality.
By 1963, the army's chief of staff secretly recommended that more than 500 nuclear warheads of various kinds, ranging up to l00 kilotonnes, would be necessary for the country's defence. One option in his report included a stock of 30 one-megatonne bombs for retaliatory attacks on "demographic" targets "in enemy hinterland".
Plans to join the nuclear arms race were buried in 1964 as doubts grew over the cost.