The United States Eighth Air Force, based at many airfields in central and southern England, and the Fifteenth Air Force, based in Italy, complemented the RAF Bomber Command's nighttime area bombing in the Combined Bomber Offensive to help secure air superiority over the cities, factories and battlefields of Western Europe in preparation for the invasion of France in 1944.
USAs Eighth Air Force, baseret på mange forskellige flyvepladser i det sydlige og mellemste England, og Fifteenth Air Force, baseret i Italien, komplementerede RAF Bomber Commands natlige fladebombning under arbejdet med at sikre luftoverlegenhed over byerne, fabrikkerne og krigszonerne i Vesteuropa, unde forberedelserne til invasionen af Frankrig i 1944.