China's repeated threats to intervene in the conflict in support of Pakistan increased pressure on the government to take an immediate decision to develop nuclear weapons. Despite repeated assurances, the United States did little to prevent extensive use of American arms by Pakistani forces during the conflict, thus irking India. At the same time, the United States and United Kingdom refused to supply India with sophisticated weaponry which further strained the relations between the West and India. These developments led to a significant change in India's foreign policy – India, which had previously championed the cause of non-alignment, distanced itself further from Western powers and developed close relations with the Soviet Union. By the end of the 1960s, the Soviet Union emerged as the biggest supplier of military hardware to India. From 1967 to 1977, 81% of India's arms imports were from the Soviet Union. After the 1965 war, the arms race between India and Pakistan became even more asymmetric and India was outdistancing Pakistan by far. India's defence budget too would increase gradually after the war, in 1966-1967 it would rise to 17% and by 1970-1971 it would rise to 25% of its revenue. However, according to the world bank data India's defence expenditure by GDP decrease from 3.871% in 1965 to 3.141% in 1969, thereafter slightly increased to 3.652% in 1971.