In South Korea is protected by the U.S troops. South Korea has the most technologically advanced economies. Leader, Kim Jong Un, has threatens us. By threatened us by launching a "pre-emptive nuclear strike" between South Korea and the United States.
The United States declared that they would spend $1 million on missile defenses in Alaska and California.
After the war world war ended in 1945, North Korea invaded South Korea. Then the U.S.A step in and helped South Korea.