In The Simpsons, which war did Seymour Skinner serve in the USA Army as a Green Beret?

Seymour Skinner, a character from The Simpsons, served in the US Army as a Green Beret during the Vietnam War because the show's creators intended to reflect the societal turmoil and historical context of that era. By depicting Skinner as a veteran of the Vietnam War, The Simpsons tackled significant issues and provided commentary on the impact of the war on individuals and society at large. This choice also added depth to Skinner's character, as his military experience shaped his behavior and leadership style as the elementary school principal.