In January 1943, Rostow was given the task of identifying the key industries that supported the German war economy. As an intelligence analyst, Rostow became convinced in 1943 that oil was Germany's Achilles heel, and if the United States Army Air Force were to target the Romanian oil fields together with the plants for making artificial oil and oil shortage facilities within Germany itself, then the war would be won, a strategy known as the "Oil Plan". By early 1944, Rostow had finally won over General Carl Spaatz to the merits of the "Oil Plan". In early 1944, there was much debate about the merits of the "Oil Plan" vs. the "Transportation Plan" of targeting the German and French railroad system. The "Transportation Plan" was implemented first as part of the run-up to Operation Overlord. The "Oil Plan" began to be implemented as a strategy by the Army Air Force in May 1944, which Rostow later called a disastrous error, claiming if the "Oil Plan" had been adopted earlier, the war would have been won far earlier. He also claimed that the United States would have entered into the Cold War in a far stronger position as he always maintained that if "Oil Plan" had been adopted earlier it would have allowed the U.S. Army to push deeper into Central Europe and even into Eastern Europe. Based on his World War II experiences, Rostow became a convinced advocate of strategical bombing, arguing that it was the bombing campaign against Germany's cities that had won the war. For his work with the Enemy Objectives Unit during the war, Rostow was awarded an OBE.