The correct answers are A) the United States estimated that the war would cost much more money and time than it really did, and C) the United States entered the war in order to make Vietnam a U.S. colony.
The factors in the US's failure to achieve its goals in Vietnam were that the United States estimated that the war would cost much more money and time than it really did, and the United States entered the war in order to make Vietnam a U.S. colony.
After the Tet Offensive, many people in the United States started questioning the United States participation in the War of Vietnam. Protesters took the streets and marched against the war and demanded that the troops returned to America. Many lives were lost at that time, and millions of dollars had been invested in the war effort. The United States government wanted Vietnam to be a US colony in order to stop the spread of Communism supported by the Soviet Union. But the cost was too high.
