I wouldn’t say Korea is currently at war.

It’s true the Korean War never formally ended. There’s a ceasefire, but no peace treaty. But we don’t measure wars by formal declarations anymore. The last time the United States formally declared war was WWII, but we still consider Vietnam, Iraq and other armed conflicts to be wars. In that sense, war means active fighting. There’s currently active fighting in Afghanistan, but not the Korean peninsula.

The United States has troops stationed in many locations around the world, some of which guard against potentially hostile neighboring powers (as in the Baltics), and some of which focus on things like logistics and medicine (as in Germany). The DMZ in Korea is the most heavily armed, and the troops stationed on or near it face considerable risk if conflict breaks out.

But that’s the distinction with Afghanistan. It’s not a question of “if.” There’s active fighting there, and has been for years, as opposed to Korea.