アングロ＝イラク戦争
The Arab Legion returned to H3 on the morning of 10 May, and found No. 2 Armoured Car Company RAF under Squadron Leader Michael Casano waiting there. They had been sent up ahead of the main column to assist the Arab Legion in taking Rutbah. Casano took his RAF armoured cars to Rutbah whilst the Arab Legion replenished their supplies at H3. Casano's armoured cars fought an action against al-Qawuqji's trucks for most of the rest of the day, and although the result was not decisive the trucks retired to east under the cover of dark to leave the garrison to its fate. That night the RAF succeeded in a night bombing, with several bombs landing inside the fort.
Following the withdrawal of al-Qawuqji's trucks and the successful bombing by the RAF, the garrison withdrew from the fort under the cover of dark. In the morning, the Arab Legion column arrived and garrisoned the fort whilst Casano's armoured cars continued to fight remnants of the Iraqi Desert Police's forces.
The force put together in Palestine by Wavell was codenamed Habforce, short for Habbaniya Force. The force was placed under the command of Major-General George Clark, who was the commander of the 1st Cavalry Division. After Wavell complained that using any of the force stationed in Palestine for service in Iraq would put Palestine and Egypt at risk, Churchill wrote Hastings Ismay, Secretary of the Chiefs-of-Staff Committee, and asked: "Why would the force mentioned, which seems considerable, be deemed insufficient to deal with the Iraq Army?" Concerning the 1st Cavalry Division specifically, he wrote: "Fancy having kept the cavalry division in Palestine all this time without having the rudiments of a mobile column organised!" On balance, Wavell wrote that the 1st Cavalry Division in Palestine had been stripped of its artillery, its engineers, its signals, and its transport to provide for the needs of other formations in Greece, North Africa, and East Africa. While one motorised cavalry brigade could be provided, this was only possible by pooling the whole of the divisional motor transport.
It was after the TJFF refused to enter Iraq that Clark decided to divide Habforce into two columns. The first column was a flying column codenamed Kingcol. Kingcol was named after its commanding officer, Brigadier James Kingstone, and was composed of the 4th Cavalry Brigade, two companies of the 1st battalion The Essex Regiment, the Number 2 Armoured Car Company RAF, and 237 Field Battery of 25 pounder howitzers from 60th (North Midland) Field Regiment, Royal Artillery. The second column, the Habforce main force, under the command of Lieutenant-Colonel J. S. Nichols, was composed of the remaining elements of the 1st battalion The Essex Regiment, the remainder of the 60th Field Regiment, RA, one anti-tank battery, and ancillary services. In addition to Kingcol and the Habforce main force, there was available to Major-General Clark a 400-man strong detachment of the Arab Legion (al-Jaysh al-Arabī) in the Emirate of Transjordan. The Arab Legion consisted of three mechanised squadrons transported in a mixture of civilian Ford trucks and equipped with home-made armoured cars. Unlike the TJFF, the Arab Legion was not part of the British Army. Instead, the Arab Legion was the regular Army of Transjordan and it was commanded by Lieutenant-General John Bagot Glubb, also known as "Glubb Pasha."
During the morning of 11 May, Kingcol departed from Haifa with orders to reach Habbaniya as quickly as possible. The occasion was the last all-horse operation in British military history. On 13 May, Kingcol arrived in Rutbah but found no military presence there. Glubb Pasha and the Arab Legion had already moved on. The flying column under Brigadier Kingstone then conducted maintenance at Rutbah before moving on themselves. On 15 May, the first contact was made with the Iraqi military when a Blenheim bomber strafed the column and dropped a bomb; no damage was inflicted and no casualties were sustained. On 16 May, further bombing attacks were made against the column when it was attacked by the Luftwaffe, again no damage was sustained but there were a few casualties.
Also on 15 May, Fraser went sick and was replaced as the commander of the 10th Indian Division. His illness had led to him losing the confidence of his own staff and he was replaced by the newly promoted Major-General William Slim. Slim would go on to show himself as one of the most dynamic and innovative British commanders of the war. Also in early May, Longmore was replaced as Air Officer Commanding in the Middle East by his deputy, Sir Arthur Tedder.
During the late evening of 17 May, Kingcol reached the vicinity of Habbaniya. The next morning the column entered the RAF base and throughout the day the remainder of the 1st battalion The Essex Regiment were airlifted into the base. The force dispatched from Palestine to relieve the Iraqi siege of RAF Habbaniya arrived about 12 days after the siege was lifted.
With Habbaniya secure, the next objective for British forces was to secure the town of Fallujah as a preliminary objective before being able to march on Baghdad. An Iraqi Brigade group was holding the town and bridge of Fallujah denying the road to Baghdad; a further Brigade group was holding the town of Ramadi, west of Habbaniya, barring all movement westwards. Colonel Roberts dismissed the idea of attacking Ramadi because it was still garrisoned heavily by the Iraqi Army and was largely cut off by self-imposed flooding. Roberts would leave Ramadi isolated and, instead, secure the strategically important bridge over the Euphrates at Fallujah.
In the week following the withdrawal of the Iraqi forces near Habbaniya, Colonel Roberts formed what became known as the Habbaniya Brigade. The brigade was formed by grouping the 1st battalion The Essex Regiment from Kingcol with further infantry reinforcements that had arrived from Basra, the 2nd battalion 4th Gurkha Rifles, and some light artillery.
During the night of 17–18 May, elements of the Gurkha battalion, a company of RAF Assyrian Levies, RAF Armoured Cars and some captured Iraqi howitzers crossed the Euphrates using improvised cable ferries. They crossed the river at Sin el Dhibban and approached Fallujah from the village of Saqlawiyah. During the early hours of the day, one company of the 1st battalion KORR were air transported by 4 Valentias and landed on the Baghdad road beyond the town near Notch Fall. A company of RAF Assyrian Levies, supported by artillery from Kingcol, was ordered to secure the bridge across the river. Throughout the day the RAF bombed positions in the town and along the Baghdad road, avoiding a general bombardment of the town because of the civilian population. On 19 May 57 aircraft began bombarding Iraqi positions within and around Fallujah before dropping leaflets requesting the garrison to surrender; no response was given and further bombing operations took place. The RAF dropped ten tons of bombs on Fallujah in 134 sorties.
During the afternoon a ten-minute bombardment of Iraqi trenches near the bridge was made before the Assyrian Levies advanced, covered by artillery fire. Facing little opposition they captured the bridge within 30 minutes; they were then met by an Iraqi envoy who offered the surrender of the garrison and the town. 300 prisoners were taken and no casualties had been sustained by the British force. The Luftwaffe responded to the British capture of the city by attacking the Habbaniya airfield, destroying and damaging several aircraft and inflicting a number of casualties. On 18 May, Major-General Clark and AVM D'Albiac arrived in Habbaniya by air. They determined not to interfere with the ongoing operations of Colonel Roberts. On 21 May, having secured Fallujah, Roberts returned to Shaibah and to his duties with the 10th Indian Infantry Division.
On 22 May, the Iraqi 6th Infantry Brigade, of the Iraqi 3rd Infantry Division, conducted a counter-attack against the British forces within Fallujah. The Iraqi attack started at 02:30 hours supported by a number of Italian-built L3/35 light tanks. By 03:00 the Iraqis reached the north-eastern outskirts of the town. Two light tanks, which had penetrated into the town, were quickly destroyed. By dawn British counter-attacks had pushed the Iraqis out of north-eastern Fallujah. The Iraqis now switched their attack to the south-eastern edge of the town. But this attack met stiff resistance from the start and made no progress. By 10:00 Kingstone arrived with reinforcements, from Habbaniya, who were immediately thrown into battle. The newly arrived infantry companies, of the Essex Regiment, methodically cleared the Iraqi positions house-by-house. By 18:00 the remaining Iraqis had fled or were taken prisoner, sniper fire was silenced, six Iraqi light tanks were captured, and the town was secure. On 23 May, aircraft of Fliegerführer Irak made a belated appearance. British positions at Fallujah were strafed on three separate occasions. But, while a nuisance, the attacks by the Luftwaffe accomplished little. Only one day earlier an air assault coordinated with Iraqi ground forces might have changed the outcome of the counter-attack.
During this period of time, Glubb Pasha's Legionnaires dominated the tribal country north of Fallujah between the Euphrates and the Tigris, an area known as Jezireh. Lieutenant-General Glubb had been instructed to persuade the local tribes to stop supporting Rashid Ali's government. Using a combination of propaganda and raids against Iraqi government posts, his actions proved to be remarkably successful. The British also used this period of time to increase air activity against the northern airfields of the Luftwaffe and to finally crush the German effort to support the Iraqis.
In response to the initial Iraqi moves, the 10th Indian Infantry Division, under Major-General Fraser, occupied Basra airport, the city's docks, and the power station. Elements of the 20th Indian Infantry Brigade, under Brigadier Powell, were used to occupy these sites. Between 18 and 29 April, two convoys had landed this brigade in the Basra area. 2nd battalion 8th Gurkha Rifles guarded the RAF airfield at Shabaih, 3rd battalion 11th Sikh Regiment secured the Maqil docks, and 2nd battalion 7th Gurkha Rifles were held in reserve. Otherwise, no major operations took place in the Basra area. The principal difficulty was that there were insufficient troops to take over Maqil, Ashar, and Basra City concurrently. While the Iraqi troops in Basra agreed to withdraw on 2 May, they failed to do so. On 6 May, the 21st Indian Infantry Brigade under the command of Brigadier Charles Joseph Weld arrived and disembarked at Basra. This was the 10th Indian Infantry Division's second brigade to arrive in Iraq. The 21st Indian Infantry Brigade included 4th battalion 13th Frontier Force Rifles, 2nd battalion 4th Gurkha Rifles, and 2nd battalion 10th Gurkha Rifles.
Starting on 7 May and ending 8 May, elements of the 20th Indian Infantry Brigade and the 21st Indian Infantry Brigade captured Ashar, near Basra. Ashar was well defended and the Iraqi defenders inflicted a number of casualties on the British attackers. The British units involved were A, B, C, and D companies of 2nd battalion 8th Gurkha Rifles and a half section of Rolls Royce armoured cars from 4th battalion 13th Frontier Force Rifles. 2nd battalion 4th Gurkha Rifles were held in reserve. As a result of the successful action against Ashar, Basra City was secured without a fight. However, armed resistance from Iraqi police and Army units continued until 17 May. While the Basra area was now secured, it was flood season in Iraq, and the difficulty of northward movement from Basra by rail, road, or river towards Baghdad stifled further operations. In addition, Iraqi forces occupied points along the Tigris and along the railway to further discourage northward movement.