was just 54.6 trillion won as a comparison. Command structure Command over the ROK Armed Forces is established in the Constitution. The President is the Commander-in-Chief Forces ex officio. The military authority runs from the President to the Minister of National Defense, who is often to be (but not legally bound to be) a retired four-star general. The President and Minister of National Defense are in charge of the entire military establishment, maintaining civilian control of the military. The Minister of National Defense, by order of the President, takes charge of military affairs, and supervises the Chairman of the Joint Chiefs of Staff and the chief of staff of each service of the Armed Forces. To coordinate military strategy with political affairs, the President has a National Security Council headed by the National Security Advisor. Joint Chiefs of Staff The Joint Chiefs of Staff consists of the Chairman of the Joint Chiefs of Staff, and the military service chiefs from the Army, Navy, and Air Force. Unlike the U.S. counterpart, operational command of combat units falls within the purview of the Chairman of the Joint Chiefs of Staff who reports to the Minister of National Defense. The Chairman of the Joint Chiefs of Staff, a four-star general or admiral, is the senior officer of the Armed Forces. The Chairman of the Joint Chiefs of Staff assists the Minister of National Defense with regard to operational command authority, and supervises the combat units of each service of the Armed Forces, by order of the Minister of National Defense. The chain of operational control runs straight from the Chairman of the Joint Chiefs of Staff to the commandants of the Army, Navy, and Air Force operational commands. The respective chiefs of staff of each service branch (Army, Navy, and Air Force) has administrative control over his or her own service. Service branches The ROK Armed Forces consists of the ROK Army, ROK Navy, and ROK Air Force. The ROK Marine Corps functions as a branch of the Navy. The ROK Reserve Forces is a reserve component. ROK Army The ROK Army (ROKA) is by far the largest of the military branches, with about 420,000 personnel as of 2020. This comes as a response to both the mountainous terrain native to the Korean Peninsula (70% mountainous) as well as the heavy North Korean presence, with its 1-million-strong army, two-thirds of which is permanently