In 1971, Indira Gandhi and her Congress (R) were returned to power with a massively increased majority. The nationalisation of banks was carried out, and many other socialist economic and industrial policies enacted. India intervened in the Bangladesh War of Independence, a civil war taking place in Pakistan's Bengali half, after millions of refugees had fled the persecution of the Pakistani army. The clash resulted in the independence of East Pakistan, which became known as Bangladesh, and Prime Minister Indira Gandhi's elevation to immense popularity. Relations with the United States grew strained, and India signed a 20-year treaty of friendship with the Soviet Union—breaking explicitly for the first time from non-alignment. In 1974, India tested its first nuclear weapon in the desert of Rajasthan, near Pokhran.