This was changed after Zulfikar Ali Bhutto and democratic socialists under him decided to build nuclear weapons for the sake of their national security and survival. In 1974, U.S. imposed embargo and restriction on Pakistan to limit its nuclear weapons program. The ban was lifted in early 1975, a decision that was protested by the government of Afghanistan. In the 1980s, the American concerns of Pakistan's role in nuclear proliferation eventually turned out to be true after the exposure of nuclear programs of Iran, North Korea, Saudi Arabia and Libya. Although the atomic program was effectively peaceful and devoted for economical usage, the nuclear policy change in the 1970s and till the present, with Pakistan maintaining its program as part of the strategic deterrence.