program was aimed at the development of nuclear weapons, with Indira Gandhi carefully overseeing the development of weapons. In 1971, India gained military and political momentum over Pakistan, after a successful military campaign against Pakistan. Starting preparations for a nuclear test in 1972, India finally exploded its first nuclear bomb in Pokhran test range, codename Smiling Buddha, in 1974. During the 1980s–90s, India began development of space and nuclear rockets, which marked Pakistan's efforts to engage in the space race with India. Pakistan's own program developed space and nuclear missiles and began unmanned flight tests of its space vehicles in the mid-1990s, which continues in the present. After the defeat in the Indo-Pakistani war of 1971, Pakistan launched its own nuclear bomb program in 1972, and accelerated its efforts in 1974, after India exploded its first nuclear bomb in Pokhran test range, codename Smiling Buddha. This large-scale nuclear bomb program was directly in response to India's nuclear program. In 1983, Pakistan achieved a major milestone in its efforts after it covertly performed a series of non-fission tests, codename Kirana-I. No official announcements of such cold tests were made by Pakistan government. Over the next several years, Pakistan expanded and modernised nuclear power projects around the country to supply its electricity sector and to provide back-up support and benefit to its national economy. In 1988, a mutual understanding was reached between the two countries in which each pledged not to attack nuclear facilities. Agreements on cultural exchanges and civil aviation were also initiated, also in 1988. Finally, in 1998, India exploded its second nuclear test (see: Pokhran-II) which invited Pakistan to follow the latter's step and performed its own atomic tests (see Chagai-I and Chagai-II). Talks and other confidence-building measures After the 1971 war, Pakistan and India made slow progress towards the normalisation of relations. In July 1972, Indian Prime Minister Indira Gandhi and Pakistani President Zulfikar Ali Bhutto met in the Indian hill station of Shimla. They signed the Shimla Agreement, by which India would return all Pakistani personnel (over 90,000) and captured territory in the west, and the two countries would "settle their differences by peaceful means through bilateral negotiations." Diplomatic and trade relations were also re-established in 1976. 1990s In 1997, high-level Indo-Pakistan talks resumed after a three-year pause. The Prime Ministers of Pakistan and India met twice and the foreign secretaries conducted three rounds of talks. In