Pakistan is one of nine states to possess nuclear weapons. Pakistan began development of nuclear weapons in January 1972 under Prime Minister Zulfikar Ali Bhutto, who delegated the program to the Chairman of the Pakistan Atomic Energy Commission (PAEC) Munir Ahmad Khan with a commitment to having the device ready by the end of 1976. Since PAEC, which consisted of over twenty laboratories and projects under reactor physicist Munir Ahmad Khan, was falling behind schedule and having considerable difficulty producing fissile material, Abdul Qadeer Khan, a metallurgist working on centrifuge enrichment for Urenco, joined the program at the behest of the Bhutto administration by the end of 1974. As pointed out by Houston Wood, "The most difficult step in building a nuclear weapon is the production of fissile material"; as such, this work in producing fissile material as head of the Kahuta Project was pivotal to Pakistan developing the capability to detonate a nuclear weapon by the end of 1984. The Kahuta Project started under the supervision of a coordination board that oversaw the activities of KRL and PAEC. The Board consisted of A G N Kazi (secretary general, finance), Ghulam Ishaq Khan (secretary general, defence), and Agha Shahi (secretary general, foreign affairs), and reported directly to Bhutto. Ghulam Ishaq Khan and General Tikka Khan appointed Major General Ali Nawab as the ranking engineer on the program. Moderate uranium enrichment for the production of fissile material was achieved at KRL by April 1978. Eventually, the supervision passed to Lt General Zahid Ali Akbar Khan in President General Muhammad Zia-ul-Haq's Administration. Pakistan's nuclear weapons development was in response to the loss of East Pakistan in 1971's Bangladesh Liberation War. Bhutto called a meeting of senior scientists and engineers on 20 January 1972, in Multan, which came to be known as "Multan meeting". Bhutto was the main architect of this programme, and it was here that Bhutto orchestrated the nuclear weapons programme and rallied Pakistan's academic scientists to build an atomic bomb in three years for national survival. At the Multan meeting, Bhutto also appointed Munir Ahmad Khan as chairman of PAEC, who, until then, had been working as director at the nuclear power and Reactor Division of the International Atomic Energy Agency (IAEA), in Vienna, Austria. In December 1972, Abdus Salam led the establishment of Theoretical Physics Group (TPG) as he called scientists working at ICTP to report to Munir Ahmad