This policy complicated China’s foreign relations, and was modified in 1968. The Soviet invasion of Czechoslovakia in 1968 and Sino-Soviet border conflict in 1969 forced China to reconsider its strategy of hostility towards both Cold War superpowers, and Beijing sought to improve its relations with the United States. Sino-Gulf relations also began to change, and China began to reduce its support to Oman’s revolutionary movement gradually from 1971.