In early 1971, disputed elections in Pakistan led the then East Pakistan to declare independence as Bangladesh. Repression and violence by the Pakistani army led 10 million refugees to cross border in to India over the coming months. Finally in December 1971, Gandhi directly intervened in the conflict to liberate Bangladesh. India emerged victorious in the resulting conflict to become the dominant power of South Asia. India had signed a treaty with the Soviet Union promising mutual assistance in the case of war, while Pakistan received active support from the United States during the conflict. U.S. President Richard Nixon disliked Gandhi personally, referring to her as a "witch" and "clever fox" in his private communication with Secretary of State Henry Kissinger. Nixon later wrote of the war: "[Gandhi] suckered [America]. Suckered us...this woman suckered us.". Relations with the U.S. became distant as Gandhi developed closer ties with the Soviet Union after the war. The latter grew to become India's largest trading partner and its biggest arms supplier for much of Gandhi's premiership. India's new hegemonic position as articulated under the "Indira Doctrine" led to attempts to bring the Himalayan states under the Indian sphere of influence. Nepal and Bhutan remained aligned with India, while in 1975, after years of building up support, Gandhi incorporated Sikkim into India, after a referendum in which a majority of Sikkimese voted to join India. This was denounced as a "despicable act" by China.