One of the reasons for direct u. s military involvement in the vietnam war was the domino theory. how did this theory apply to southeast asia? a.) if vietnam became communist, china would rule southeast asia. b.) without u. s involvement in vietnam, the soviets would take over southeast asia. c.) if south vietnam fell into communism, all of southeast asia would follow. d.) both china and the soviet union wanted to install a communist regime in vietnam

The correct answer is C)  If South Vietnam fell into communism, all of Southeast Asia would follow.

One of the reasons for direct U.S military involvement in the Vietnam War was the domino theory. This theory applies to Southeast Asia in that if South Vietnam fell into communism, all of Southeast Asia would follow.

During the Cold War years in which the Soviet Union and the United States confronted in an arms race and its desire to dominate one over the other, the Domino Theory was the policy that stated that if one Communist country could spread Communism over the other neighbor country and so on, as the falling of aligned dominoes. That is why the United States decided to intervene in Vietnam. The Soviet Union wanted to spread Communism and the US wanted to stop it.

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