China invades Vietnam with at least 200,000 troops, perhaps twice that number. In response to the Vietnamese invasion of Cambodia, China occupies Vietnam. Tensions between Vietnam and China had escalated in 1975, at the end of the Vietnam War. As part of its expansionist attempt in Indochina, Vietnam established a military presence in Laos, forged ties with the Soviet Union, China’s rival, and invaded Cambodia in 1979. A month later, Chinese forces launched an invasion but were repelled in nine days of fierce fighting.
