between January and June to Osan AB, South Korea following the North Korean seizure of the vessel. Frequent deployments to South Korea have been performed ever since to maintain the air defense alert mission there. In 1972, the 1st Special Operations Squadron was assigned, bringing their specialized C/MC-130 Hercules aircraft to the wing. The squadron was reassigned in 1978. The reconnaissance mission ended in 1989 with the retirement of the RF-4Cs, and the inactivation of the 15th TRS. Post-Vietnam The F/RF-4C Phantom II replaced the F-105s in 1971, and a further upgrade to the F-15 Eagle was made in 1979. On 6 November 1972, the 18th Tactical Fighter Wing dispatched the McDonnell Douglas F-4C / D Phantom II fighter jets of the 44th Tactical Fighter Squadron and the 67th Tactical Fighter Squadron to the Ching Chuan Kang Air Base, Taiwan until 31 May 1975. Assist Taiwan ’s air defense against threats from China. The designation of the wing changed on 1 October 1991 to the 18th Wing with the implementation of the Objective Wing concept. With the objective wing, the mission of the 18th expanded to the Composite Air Wing concept of multiple different wing missions with different aircraft. The mission of the 18th was expanded to include aerial refueling with KC-135 Stratotanker tanker aircraft; and surveillance, warning, command and control E-3 Sentry, and communications. Added airlift mission in June 1992 with the C-12 Huron, transporting mission critical personnel, high-priority cargo and distinguished visitors. In February 1993, the 18th Wing gained responsibility for coordinating rescue operations in the Western Pacific and Indian Ocean. Arrival of Patriot unit In November 2006, the U.S. Army's 1st Battalion, 1st Air Defense Artillery Regiment, a Patriot PAC-III unit, deployed to Kadena from Fort Bliss Texas. Originally assigned to 31st ADA Brigade of Fort Bliss, they were reassigned to the 94th AAMDC, USINDOPACOM. The move was part of the BRAC consolidation of U.S. Army bases and security agreements between the U.S. and Japan. The battalion's mission is to defend the base against tactical ballistic missiles from North Korea. The deployment was controversial on Okinawa, being greeted with protests. Foreign units Other U.S. allies who had expressed intention with the approval of both the Japanese government and the United States Air Force to host units in the air base to further impose united cooperation against regional threats; North Korea, Russian Siberia, Russian Far East and the