A coniferous forest contains evergreen trees that bear cones. Elegant pines grow in this biome, along with spruce, fir, and tamarack. In much of the northern forest, the conifers mingle with deciduous trees, particularly aspen, birch, sugar maple, and basswood.
The United States entered the Vietnam war to prevent the spread of communism. China was already a communist country, and the United States believed that China would spread it to other Asian countries if it did not intervene. Continue Reading.
The short answer is that the US supported South Vietnam because it saw it as a democratic ally in Southeast Asia and was concerned about the spread of Communist aggression, especially that from North Vietnam under Ho Chi Minh who wanted to reunite the country by force.