U.S. Marines with 2nd Battalion, 5th Marine Regiment, 1st Marine Division, unload gear to begin Marine Aviation Support Activity 23 at Puerto Princesa International Airport, Palawan, Philippines, July 12, 2023. MASA 23 is a bilateral exercise between the Armed Forces of the Philippines and the U.S. Marine Corps, aimed at enhancing interoperability and coordination in support of U.S.-Philippine mutual defense. - U.S. Marines with 2nd Battalion, 5th Marine Regiment, 1st Marine Division, unload gear to begin Marine Aviation Support Activity 23 at Puerto Princesa International Airport, Palawan, Philippines, July 12, 2023. MASA 23 is a bilateral exercise between the Armed Forces of the Philippines and the U.S. Marine Corps, aimed at enhancing interoperability and coordination in support of U.S.-Philippine mutual defense.