Final answer:
The Vietnam War ended differently from the Korean War due to different geopolitical circumstances, military strategies, and international involvement. There was a lack of international support for South Vietnam in the same way that there was a unified stance from both Koreas in the Korean War.
Step-by-step explanation:
The Vietnam War ended differently from the Korean War due to different geopolitical circumstances, similarities in military strategies, lack of international involvement, and a unified stance from both Koreas being absent in Vietnam.
During the Vietnam War, the United States supported democratic South Vietnam, while the Soviet Union supported communist North Vietnam. The U.S. military approach of battlefield engagement did not translate well to Vietnam's guerrilla warfare tactics. Additionally, both the United States and the Soviet Union backed regimes in Vietnam that they were not enthusiastic supporters of, turning the war into a proxy war.
On the other hand, the Korean War involved nationalist and Communist forces, with the United States supporting the South and the Soviet Union supporting the North. The two sides signed an armistice, creating a divided peninsula along the 38th parallel. Despite frustrations for Americans, a stalemate was reached, and military force from either side was not allowed to enter the demilitarized zone.