Original sentence: By the time of the bombing halt during Operation Rolling Thunder in 1968, poor air-to-air combat loss-exchange ratios against the smaller, more agile enemy MiGs during the early part of the Vietnam War eventually led the USAF to establish Dissimilar Air Combat Training (sometimes referred to as Red Flag) programs and the US Navy's "Top Gun" school, formerly located at Miramar Naval Air Station in California (Now a USMC Air Station).The MiG-21 initially achieved renown in the Vietnam War, during which it saw extensive action
Edited sentence: After a million sorties and nearly a thousand lost US aircraft, Operation Rolling Thunder came to an end on 01 November 1968.Clashes; Air Combat Over North Vietnam 1965-1972.ISBN 1-59114-519-8.Michel III, Marshall L.Naval Institute Press, 1997, 2007.Poor air-to-air combat loss-exchange ratios against the smaller, more agile enemy MiGs during the early part of the Vietnam War eventually led the USAF to establish Dissimilar Air Combat Training (sometimes referred to as Red Flag) programs and the US Navy's "Top Gun" school, formerly located at Miramar Naval Air Station in California (Now a USMC Air Station).The MiG-21, which initially achieved renown during the Vietnam War, in which it saw extensive action, was designed for very short Ground Controlled Interceptor (GCI) missions, which is precisely the type of missions that it was employed for in the skies over North Vietnam