Starting his nuclear physics career in Britain, Bhabha had returned to India for his annual vacation before the start of World War II in September 1939. War prompted him to remain in India and he accepted a post of reader in physics at the Indian Institute of Science in Bengaluru, headed by Nobel laureate C.V. Raman. During this time, Bhabha played a key role in convincing the Congress Party's senior leaders, most notably Jawaharlal Nehru who later served as India's first Prime Minister, to start the ambitious nuclear programme. As part of this vision, Bhabha established the Cosmic Ray Research Unit at the Institute, began to work on the theory of point particles movement, while independently conducting research on nuclear weapons in 1944. In 1945, he established the Tata Institute of Fundamental Research in Bombay, and the Atomic Energy Commission in 1948, serving as its first chairman. In 1948, Nehru led the appointment of Bhabha as the director of the nuclear program and tasked Bhabha to develop the nuclear weapons soon after. In the 1950s, Bhabha represented India in IAEA conferences, and served as President of the United Nations Conference on the Peaceful Uses of Atomic Energy in Geneva, Switzerland in 1955. During this time, he intensified his lobbying for the development of nuclear weapons. Soon after the Sino-Indo war, Bhabha aggressively and publicly began to call for the nuclear weapons.