In the 1980s, U.S. officials said they suspected Spain had a weapons program that ended some time after 1970. The former military dictatorship was thought to have developed nuclear facilities throughout the 1960s and 1970s.
In 1968, Spain refused to sign the nuclear Non-Proliferation Treaty, but on Nov. 5, 1987 relented and signed the treaty after its initial refusal interfered with its nuclear fuel supply from other nations.
Though Spain is not thought to have had any nuclear weapons of its own, the United States maintained a naval base in the country where nuclear weapons were stored. In 1953 the United States and Spain signed the Pact of Madrid. In exchange for housing the base, Spain received $600 million in military aid and $500 million in economic aid.
In 1992, the United States closed the naval base in Torrejon.
Today, Spain complies with IAEA safeguards to maintain nuclear power plants for energy.