U.S. Marine Corps F-35B Lightning II aircraft with Marine Fighter Attack Squadron 121 (VMFA-121) depart Marine Corps Air Station Iwakuni, Japan, Sept. 18, 2017. The F-35B Lightning II aircraft joined United States Air Force, Japan and Republic of Korea Air Force aircraft in a sequenced bilateral show of force over the Korean peninsula. This show-of-force mission demonstrated sequenced bilateral cooperation, which is essential to defending U.S. allies, partners and the U.S. homeland against any regional threat. The mission is part of the continuing demonstration of the ironclad U.S. commitment to our allies against the growing threat from North Korea’s ballistic missile and nuclear programs.