For several months, there has been much talk about bringing the THAAD missile defense system to South Korea. The two specific questions have been whether South Korea will purchase the THAAD system for its military and whether the United States will deploy its own batteries to the Korean Peninsula.

Terminal High Altitude Area Defense (THAAD) is a ballistic missile defense system made in the U.S., and operated by the U.S. Army, designed to intercept short-intermediate range missiles during the terminal (descent) phase. It is considered most effective against Scuds and similar missiles, especially when they are launched at high trajectories (i.e. arcing at a high angle and reaching a high altitude relative to the ground distance traveled).