The principal source of conflict in Vietnam is with China. During the Vietnam War, North Vietnam appeared closely allied to both the Soviet Union and China against their common external enemy, the United States. This apparent alliance hid many disputes between the Soviets and Chinese, both of which were competing for influence over Vietnam. The Vietnamese, in turn, attempted to play each of their two larger presumed allies against each other. It is now apparent that the disputes among the Soviet Union, China, and Vietnam were major.
The Vietnamese fear of the Chinese is well known, and several grounds for future conflict still exist. The Vietnamese perceived themselves as being threatened by their much smaller and less developed Southeast Asian neighbors, Laos and Cambodia. This led to the occupation of most of Cambodia and Laos by Vietnamese troops. Not only did Vietnam invade Cambodia and install their own supporters in power, but they also sent more than forty thousand troops into Laos, where they shored up another government allied to them. The Chinese oppose Vietnam's involvement in both countries.
These disputes between Vietnam and its neighbors are complicated by alliances between the Chinese and various subgroups, particularly in Cambodia. Thailand, fearing the Vietnamese more than the Chinese, sides with China. The Malaysians and Indonesians support Vietnam, but Singapore supports the Chinese position. While a wider regional war does not seem likely, the grounds for future conflict may exist.
The dispute between Vietnam and China over who influences Cambodia is insignificant compared to the longer-standing conflict over the border between China and Vietnam. The boundary the Chinese crossed in 1979 had stood for hundreds of years. Even if the incursion was only a few miles in dense inhospitable jungle, national pride for both China and Vietnam is important. For different reasons, both sides may feel that they lost face: the Chinese because of the heavy casualties and the Vietnamese because of the lost territory.
An additional significant conflict between Vietnam and China exists over a number of island groups claimed by both China and Vietnam, most particularly the Spratly Islands at the very southern edge of the South China Sea. While there are some Chinese communities in the more remote southern islands of this chain, the principal source of conflict is not the occupants on the islands but the contents of the seabed in the area surrounding the islands. Any country that can enforce its claim on the Spratly Islands is then able to make claims on the various natural resources, particularly oil, thought to exist there.
While Vietnam is principally concerned about its relationship to China, its claims to the Spratly Islands and other island groups
Also raise the possibility of conflicts with Indonesia and the Philippines.