'Halpro' (i) was the US semi-official designation of the bombing of the oilfields and oil installations at Ploiești in Romania in the US Army Air Forces' first mission against a target in Europe and the first on this strategically important Axis asset (12 June 1942).

The USAAF began planning the build-up of US air power in the Middle East during January 1942 in response to a British request. The first unit to arrive in the theatre was given the codename 'Halpro' (Halverson project)and, under the command of Colonel Harry A. Halverson, comprised 23 Consolidated B-24D Liberator heavy bombers with hand-picked crews. Thus unit had initially been assigned to the China-Burma-India Theater to attack Japan from airfields in China, but after the fall of Rangoon the Burma Road was cut so the detachment could not be logistically supported in China.

The first mission of 'Halpro' was flown on 12 June against the Romanian oil facilities at Ploieşti. Thirteen B-24 bombers took off from Fayid in Egypt during the night of 11/12 June, and of these 12 aircraft attacked at dawn. Four of the 13 aircraft later landed at a British base in Iraq which had been designated for recovery of the flight, three others landed at different Iraq airfields, two landed in Syria, and were interned in Turkey after landing in that country. Although the damage inflicted on the target was negligible, the raid was significant as the first USAAF combat mission in the European, African and Middle Eastern theatres in World War II, and as the first attack on a target which later become famous, indeed notorious, for its general survivability.

On 15 June seven B-24D bombers assisted the Royal Air Force in attacking an Italian naval force which had put to sea to intercept the British 'Vigorous' resupply convoy on its way to Malta. The 'Halpro' aircraft then flew in support of the British forces fighting in the Western Desert theatre of Egypt and Libya, and the primary task of the 'Halpro' bombers became the interdiction of supplies being delivered by sea to the Axis forces in North Africa by bombing Axis convoys at sea or in the ports of Tobruk and Benghazi.

On the same day the US Army Forces in the Middle East command was created to replace both the North African Mission in Cairo and the Iranian Mission in the Persian Corridor, and on the following day the US Department of War named Brigadier General Russell L. Maxwell as the first commander of USAFIME: an army general rather than an AAF general was named because at the time it was still expected that there would be a large US Army land force contribution to the campaign. The next day the Department of War informed Maxwell that the Halverson detachment would remain in Egypt as a part of USAFIME.

In anticipation of the arrival of US air groups, the Department of War sent Major General Lewis H Brereton, commander of the US 10^th AAF in India, to Cairo for temporary duty to assist the British forces, and he arrived in Cairo on 25 June together with nine Boeing B-17 Flying Fortress heavy bombers.

On 30 June Brereton ordered the B-17 machines which he had brought from India to move their operations to Palestine, and the 'Halpro', or rather the Halverson Detachment as it had now become, joined them at Lydda in Palestine. Both units flew day and night bombing missions against the Axis' increasingly inadequate supply lines, concentrating their efforts against the port of Tobruk.

The heavy bombers of the Brereton and Halverson Detachments (now combined into the 1^st Provisional Group, under Halverson’s command) had been flying with the British air forces for some time and, drawing on that experience, the 98^th Bombardment Group (Heavy) which arrived in mid-August 1942, was able to go directly into action. The 1^st Provisional Group provided the nucleus of the 376^th Bombardment Group in October 1942.

When the 12^th Bombardment Group (Medium) and the 57^th Fighter Group arrived in the theatre operations, they entered a highly co-operative type of air warfare in an unfamiliar desert environment. Initially, they were integrated into comparable RAF formations, allowing them to observe first-hand the complex techniques of air/surface co-ordination which the British forces had been developing during their years of fighting in the Western Desert.

To co-ordinate the growing US presence the US Army Middle East Air Force had established the IX Bomber Command and IX Fighter Command. In November Lieutenant General Frank M. Andrews assumed command of USAFIME in succession to Maxwell. Andrews was an experienced airman, and one of his first acts was to establish the 9^th AAF to replace USAMEAF. The appointment of a USAAF officer to succeed a US Army officer reflected the fact that the force would remain an air force and that US ground forces would not be taking part in the campaign.

Brereton assumed command of the new organisation and established the IX Air Service Command, which joined the IX Bomber Command and the IX Fighter Command as the major subordinate headquarters. The 376^th Bombardment Group, originally organised to support Soviet forces, became part of the IX Bomber Command, and flew its first combat missions over the deserts of North Africa.

The US Army’s Egypt-Libya Campaign ended on 12 February 1943, when the Allied forces finally succeeded in driving all Axis forces out of Libya.