The McDonnell Douglas F-4J Phantom II was a powerful, twin-engine, Mach 2 fighter developed for the U.S. Navy and Marine Corps. Built for fleet air defense and all-weather combat, the F-4J featured improved radar, engines, and weapons systems over earlier Phantom variants. It saw extensive service during the Vietnam War as an interceptor, fighter, bomber, and reconnaissance escort, becoming one of the most iconic American combat aircraft of the Cold War.