The Republic of Korea Navy, also known as the ROK Navy, is the naval warfare service branch of the South Korean armed forces, responsible for conducting naval operations and amphibious landing operations. The ROK Navy includes the Republic of Korea Marine Corps, which is a quasi-autonomous organization. Established in 1945, the ROK Navy is the oldest branch of the South Korean armed forces. Since the Korean War, the ROK Navy has concentrated its efforts to building naval forces to counteract the North Korean navy, which has littoral naval capabilities. ROK Navy strives to build larger and better equipped fleets to deter aggression, to protect national maritime rights and to support the nation's foreign policy. As a part of its mission, the ROK Navy has engaged in several peacekeeping operations since the turn of the 21st century. As of 2015, the ROK Navy has about 70,000 regular personnel including 29,000 Republic of Korea Marines. In addition, there are about 130 commissioned ships in service with the ROK Navy, including about 15 submarines, 100 surface combatants and patrol vessels, 10 amphibious warfare ships, 10 mine warfare ships, and 10 auxiliary ships (with a total displacement of about 197,000 tonnes. The naval aviation force consists of about 70 fixed-wing and rotary-wing aircraft. The ROK Marine Corps has about 400 tracked vehicles including self-propelled artillery.