Which parallel was reinforced during the Korean War?

The 38th Parallel is significant in the context of the Korean War because it served as the dividing line between North Korea and South Korea prior to and during the conflict. This line was established in 1945 at the end of World War II as part of the Allied agreement to oversee the surrender of Japanese forces in Korea.

During the Korean War, which began in 1950, North Korean forces invaded South Korea, crossing the 38th Parallel, which prompted a military response from the United States and other United Nations member nations to support South Korea. Subsequently, the 38th Parallel became a crucial frontline during the war, with battles taking place around this demarcation line as it was pushed back and forth between the two opposing sides. The war ultimately ended in an armistice in 1953, effectively maintaining the division along the 38th Parallel and leading to the creation of the Korean Demilitarized Zone (DMZ) that exists today.

This context underscores the importance of the 38th Parallel in terms of military strategy and geopolitical significance during the Korean War, making it the correct choice for the question regarding which parallel was reinforced during that time.