More than 50 U.S. aircraft from three U.S. bases were used in a joint exercise where the largest USAF base would be under a simulated attack. Called the WestPac Rumrunner, the Navy, Marines, Army, Air Force, and airmen and aircraft from Kadena were all involved in the exercise. The mission focused on a defensive counter-air scenario but included water rescue training and forward air refueling, all while communications to headquarters were cut off. The exercise also only used assets from the Western Pacific, creating a more realistic first response to an attack in the region.
Source: https://www.airforcemag.com/grassroots-kadena-exercise