before withdrawing with the ROC government to Taiwan in 1949. After 1949, the ROC Army has participated in combat operations on Kinmen and the Dachen Archipelago against the PLA in the Battle of Kuningtou, and in the First and Second Taiwan Strait Crisis. In addition to these major conflicts, ROCA commandos were regularly sent to raid the Fujian and Guangdong coasts. Until the 1970s, the stated mission of the Army was to retake the mainland from the People's Republic of China. Following the lifting of martial law in 1987 and the democratization of the 1990s, the mission of the ROC Army has been shifted to the defense of Taiwan, Penghu, Kinmen and Matsu from a PLA invasion. With the reduction of the size of the ROC armed forces in recent years, the Army has endured the largest number of cutbacks as ROC military doctrine has begun to emphasize the importance of offshore engagement with the Navy and Air Force. Subsequent to this shift in emphasis, the ROC Navy and Air Force have taken precedence over the ROC Army in defense doctrine and weapons procurement. Recent short-term goals in the Army include acquisition and development of joint command and control systems, advanced attack helicopters and armored vehicles, Multiple Launch Rocket System and field air defense systems. The Army is also in the process of transitioning to an all volunteer force. During the COVID-19 pandemic Army chemical warfare units were used to disinfect public areas and to do spot disinfections around known disease clusters. In January 2021 the 33rd Chemical Warfare Group was deployed to Taoyuan City to deal with a cluster of infections around a hospital there. Equipment From the 1990s onwards, the Republic of China Army launched several upgrade programmes to replace outdated equipment with more advanced weapons, also increasing its emphasis on forces that could be rapidly deployed and were suited for combat in Taiwan's heavily urbanized environment. Orders were placed with the United States for M60A3 Patton tanks, M109A5 "Paladin" howitzers and AH-1W SuperCobra attack helicopters, as well as updating existing equipment. Along with the other ROC military branches, the ROC Army has extensive experience in the construction and utilization of tunnels and bases gained during the People's Republic of China's bombardments of Kinmen and Matsu during the Cold War and many facilities are rumoured to be located underground in undisclosed locations. The U.S. Government announced on October