Book excerpt: The Vietnam War placed unexpected demands upon American military forces and equipment.The principal US naval fighter, the McDonnell F-4 Phantom, had originally been designed to defend the Fleet from air attack at long range. However, its tremendous power and bomb-carrying capacity made it an obvious candidate for the attack mission in Vietnam from 1965 onwards. Its opponent was the MiG-17, a direct descendant of the MiG-15, which had given USAF Sabre jets a hard fight in the Korean War. This book brings to life their dangerous duels and includes detailed cockpit views and other specially commissioned artwork to highlight the benefits and shortcomings of each plane type. It was in the skies over Vietnam that many of the techniques of air combat evolved as pilots learned how to use and to defeat supersonic fighters for the first time.