While the US military's current first-line aircraft remain formidable weapons, their basic designs are decades old, and the services would like to obtain more modern aircraft to fit their future needs. The US Air Force, the US Navy (USN), the US Marine Corps (USMC), and the British Royal Navy (RN) have now committed to a new, advanced attack aircraft, the Lockheed Martin F-35 "Joint Strike Fighter (JSF)". This document outlines the history of the JSF effort.