18 May 1974 - Smiling Buddah
On 18 May 1974, India conducted its first nuclear explosion. The Indian government claimed the test was for peaceful purposes only, naming it "Smiling Buddha".
The explosion, which yielded 12 kilotons according to Indian authorities, involved a fission device using plutonium. The Indian scientists used the CIRUS (Canada India Research Utility Service) reactor, for which Canada provided technical expertise and financing, while the United States supplied the heavy water.
In a bilateral agreement, Canada and India had agreed that the reactor would be employed for "peaceful purposes only". In the aftermath of the atomic explosion, Canada promptly cut off nuclear exports to India. The test also triggered the formation of the Nuclear Supplier Group (NSG), a multinational body whose objective is to further limit the export of nuclear technology and equipment to avoid their potential misuse for weapon purposes.
India subsequently conducted a series of nuclear explosions in May 1998, which it declared as nuclear weapon tests.
Prior to the 1974 and 1998 nuclear tests, India had spearheaded the movement to ban nuclear testing. Indian Prime Minister Jawaharlal Nehru proposed a nuclear "standstill' agreement in 1954. A first milestone for nuclear arms control was reached with the 1963 Partial Test Ban Treaty, which limited nuclear testing to the underground.
The 1996 Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans all nuclear explosions. Of the 44 countries that must ratify the Treaty so that it may enter into force, 36 have already done so. Of the eight remaining, China, Egypt, Iran, Israel and the United States have already signed the Treaty. India and Pakistan, together with the Democratic People's Republic of Korea, have yet to sign and ratify.