Terminal High Altitude Area Defense (THAAD), formerly Theater High Altitude Area Defense, is a United States Army anti-ballistic missile system designed to shoot down short, medium, and intermediate range ballistic missiles in their terminal phase using a hit-to-kill approach. The missile carries no warhead but relies on the kinetic energy of the impact to destroy the incoming missile. A kinetic energy hit minimizes the risk of exploding conventional warhead ballistic missiles, and nuclear tipped ballistic missiles will not explode upon a kinetic energy hit, although chemical or biological warheads may disintegrate or explode and pose a risk of contaminating the environment. THAAD was designed to hit Scuds and similar weapons.

According to a statement released On July 7, 2016, the Pentagon announced it is conducting formal feasibility studies for placement of a THAAD battery in South Korea “as a defensive measure to ensure the security of the ROK(Republic of Korea) and its people and to protect alliance military forces from North Korea’s weapons of mass destruction and ballistic missile threats.”After North Korea's reported launch of three Rodong missiles near the coast of Japan on September 5, 2016, Beijing publicly voiced opposition to such a deployment, citing concerns that it would not be "conducive to strategic stability in the region, and could intensify disputes."