Final answer:
The United States took various actions to prevent the spread of communism by armed insurgents, such as intervening in Vietnam, supporting the mujahideen in Afghanistan, and training Cuban exiles to invade Cuba.
Step-by-step explanation:
The United States took various actions to prevent the spread of communism by armed insurgents. One example is the US intervention in Vietnam, where they supported South Vietnam against the communists in the north. Another example is the US support for the mujahideen in Afghanistan, who fought against the pro-Soviet Afghan regime. Additionally, the US trained Cuban exiles in Florida to launch an invasion of Cuba in an effort to defeat Castro without committing American troops.