U.S. Air Force F-15 fighters jets from Massachusetts Air National Guard’s 104th Fighter Wing and Royal Canadian Air Force CF-18 fighter jets from 3 Wing, Bagotville, Quebec join up behind a Maine Air National Guard KC-135 Stratotanker from the 101st Air Refueling Wing during a Continental U.S. North American Aerospace Defense Command Region and Canadian NORAD Region cross-border demonstration, April 23, 2020. Aircrew and members of the Air National Guard and Royal Canadian Air Force practiced tactical-intercept skills in an air defense exercise designed to reinforce interoperability across the United States and Canadian border. A bi-national Canadian and American command, NORAD employs a network of space-based, aerial and ground-based sensors, air-to-air refueling tankers, and fighter aircraft, controlled by a sophisticated command and control network to deter, detect and defend against aerial threats that originate outside or within North American airspace. (U.S. Air National Guard Photo courtesy of Capt. Kyle Tufts)