<P> Despite its successes, by the spring of 1944 the Combined Bomber Offensive had failed to severely damage the German economy or significantly interrupt production of a vital item . The oil campaign was the first to accomplish these goals . The US strategic bombing survey identified "catastrophic" damage . Of itself, German industry was not significantly affected by attacks on oil targets as coal was its primary source of energy . And in its analysis of strategic bombing as a whole the USSBS identified the consequences of the breakdown of transportation resulting from attacks against transportation targets as "probably greater than any other single factor" in the final collapse of the German economy . </P> <P> Several prominent Germans, however, described the oil campaign as critical to the defeat of Nazi Germany . Adolf Galland, Inspector of Fighters of the Luftwaffe until relieved of command in January 1945, wrote in his book "the most important of the combined factors which brought about the collapse of Germany", and the Luftwaffe's wartime leader, Hermann Göring, described it as "the utmost in deadliness". Albert Speer, writing in his memoir, said that "It meant the end of German armaments production ." It has been stated to have been "effective immediately, and decisive within less than a year". Luftwaffe Field Marshal Erhard Milch, referring to the consequences of the oil campaign, claimed that "The British left us with deep and bleeding wounds, but the Americans stabbed us in the heart ." </P> <P> The following statistics are from the British Bombing Survey Unit . Figures are for the oil campaign in the last year of the war . </P> <P> Number of attacks by the RAF and USAAF against oil targets: </P>

Which country had the biggest oil related success leading up to world war ii