Major sources and definitions Geography Vietnam occupies the eastern and southern part of the Indochinese peninsula in Southeast Asia, with the South China Sea along its entire coast.
China is to the north and Laos and Cambodia to the west.
Long and narrow on a north-south axis, Vietnam is about twice the size of Arizona. The Mekong River delta lies in the south. Government Communist state. The Vietnamese are descendants of nomadic Mongols from China and migrants from Indonesia. B.C. China ruled the nation then known as Nam Viet as a vassal state from 111 B.C. until the 15th century, an era of nationalistic expansion, when Cambodians were pushed out of the southern area of what is now Vietnam.