Provisional Government of Bangladesh was the country's first government. The Provisional Government was formed in Mujibnagar on 17 April 1971. It issued the proclamation of independence and drafted an interim constitution, declaring "Equality, Human Dignity and Social Justice" as its fundamental principles. Its prime minister was Tajuddin Ahmad and military chief of staff was M A G Osmani. Other important cabinet members included Syed Nazrul Islam and Muhammad Mansur Ali. It included the newly formed Bangladesh Civil Service with defecting members of the Civil Service of Pakistan. It also had a prominent diplomatic corps, led by Abu Sayeed Chowdhury, Humayun Rashid Choudhury and Rehman Sobhan among others. The Bangladesh Forces included eleven sector commanders, among whom prominent figures included Ziaur Rahman, Khaled Mosharraf and K M Shafiullah. Neighboring India provided diplomatic, economic and military support for the Provisional Government. The government's capital in exile was Calcutta. The Indian military intervened in the final two weeks of the war in December 1971, ensuring the surrender of Pakistan. Sheikh Mujib administration The left-wing Awami League, which had won the 1970 election in Pakistan, formed the first post-independence government in Bangladesh. Awami League leader Sheikh Mujibur Rahman became the 2nd Prime Minister of Bangladesh on 12 January 1972 and is widely regarded as the nation's independence hero and founding father. Nation-building under his regime was based on secular Bengali nationalist principles. The original Constitution of Bangladesh, drafted by Dr. Kamal Hossain, laid down the structure of a liberal democratic parliamentary republic with socialist influences in 1972. On the international stage, Rahman and his Indian counterpart Indira Gandhi signed the 25-year Indo-Bangladeshi Treaty of Friendship, Cooperation and Peace. Bangladesh joined the Organization of the Islamic Conference, the Commonwealth of Nations and the Non-Aligned Movement. Rahman was invited to Washington DC and Moscow for talks with American and Soviet leaders. In the Delhi Agreement of 1974, Bangladesh, India and Pakistan pledged to work for regional stability and peace. The agreement paved the way for the return of interned Bengali officials and their families stranded in Pakistan, as well as the establishing of diplomatic relations between Dhaka and Islamabad. Japan became a major aid provider to the new country. Although Israel was one of early countries to recognise Bangladesh, the government in Dhaka strongly supported Egypt during the Arab-Israeli War of 1973. In return, Egypt gifted Bangladesh's military with 44 tanks. Many Eastern European countries, particularly