Attack against the Rumanian oil refinery at Ploesti on the 1st August 1943
In May 1942 an organisation, referred to as Halpro (after its commander Colonel Harry Halverson), was dispatched from the US with twenty four B-24s destined for China to make a morale boosting raid on Japan. The Liberators got no further than the Middle East when the plan for the attack was deferred. Halpro was directed to make an attack on Ploesti. The mission, flown from Fayid, Egypt on the night of the 11th/12th June, involved thirteen B-24s and did little if any damage. It did however alert the Germans to Allied interest and indicate the potential of the USAAF heavy bomber.
At the Casablanca Conference Roosevelt and Churchill discussed strategy once the Germans were expelled from Africa. One of the directives was for the Ninth Air Force to bomb Ploesti after completion of the Africa campaign and prior to the invasion of Sicily. The plan was called Tidal Wave. Colonel Jacob Smart was assigned to establish the bombing plan and he flew to England to enlist support. Smart was briefed that the refineries consisted of a dozen plants ringed around the city. A decision was made to bomb seven major refineries with the aircraft attacking at very low altitude.