by approving a long-term shipbuilding plan for the ocean-going navy. In the first decade of the 21st century, the ROK Navy launched the lead ships of larger and better equipped warships with local shipbuilders: In 2002, ROKS Chungmugong Yi Sunshin (DDH 975), a 4,500-ton destroyer, was launched; in 2005, the 14,000-ton amphibious warfare ship, ROKS Dokdo (LPH 6111) was launched; in 2006, the ROK Navy launched ROKS Sohn Wonyil (SS 072), an 1,800-ton Type 214 submarine with Air-Independent propulsion (AIP) system. In 2007, the ROK Navy launched the lead ship (DDG 991) of Sejong the Great-class destroyers with the Aegis Combat System. The ROK Navy completed a new naval base called Jeju Civilian-Military Complex Port in 2016 on the southern coast of Jeju Island to protect the sea lines of communication. In order to support ocean-going operations, the ROK Navy commissioned the 10,000-ton logistics support ship, ROKS Soyang (AOE 51), and launched the first locally designed 3,000-ton submarine, Dosan Ahn Changho (SS 083) in 2018. The ROK Navy continues to upgrade ongoing shipbuilding programs such as the Korean Submarine (KSS), Korean Destroyer Experimental (KDX), Frigate Experimental (FFX), and Landing Transport Experimental (LPX). The ROK Navy aims to become a blue-water navy in the 2020s. ROK Marine Corps The ROK Marine Corps (ROKMC) is a branch of the Republic of Korea Navy responsible for amphibious operations, and also functions as a rapid reaction force and a strategic reserve. The ROK Marine Corps, with 29,000 personnel, is organized into two divisions and two brigades. The ROK Marine Corps has about 300 tracked vehicles including assault amphibious vehicles, main battle tanks, and self-propelled artillery. The Commandant of the Republic of Korea Marine Corps is a three-star general. Following the bombardment of Yeonpyeong Island in 2010 and the subsequent establishment of the Northwest Islands Defense Command (NWIDC), the Commandant of the ROKMC has been dual-hatted as the Commander NWIDC. ROK Air Force The ROK Air Force (ROKAF) maintains a modern air force in order to defend itself from various modes of threats, including the North Korean Army. The ROK Air Force fields some 450 combat aircraft of American design. In contrast, the North Korean Army has roughly 650 combat aircraft, but mostly obsolete types of Soviet and Chinese origin. Korea began a program for the development of indigenous jet trainers beginning in 1997. This project eventually culminated in the KAI T-50, dubbed the "Golden