By 1939 Iraq was "independent" by treaty but still tethered to Britain through base rights at Habbaniya and Shaibah and transit clauses from the 1930 Anglo-Iraqi Treaty. As war widened, a nationalist current inside the army—later called the Golden Square—saw those terms as infringements on sovereignty. On April 3, 1941, Prime Minister Rashid ʿAlī al-Gaylani rode that sentiment to power, ousting the Regent ʿAbd al-Ilah and pivoting toward the Axis to counterbalance London. Britain, citing treaty rights and the security of Gulf oil and the India–Mediterranean route, resolved to intervene.
The Anglo-Iraqi War (May 2–31, 1941) was short but consequential. Iraqi forces ringed RAF Habbaniya on the Euphrates; the base—mostly a flying-training school with obsolescent aircraft—struck first, flying near-continuous sorties while a relief column (Habforce) drove from Palestine and Indian brigades landed at Basra. The Iraqi army faltered under pressure, and the coup regime collapsed by the end of May; Rashid ʿAlī fled abroad. The campaign also drew in the Axis: a small Luftwaffe detachment (Fliegerführer Irak) and Italian aircraft reached Mosul via Vichy-controlled Syria, prompting British raids against German planes and contributing to Britain's rapid June–July invasion of Syria–Lebanon to shut those air routes.
The Farhud
The aftermath was darkest for Baghdad's Jews. As the Regent returned and British columns encircled the capital, violence erupted on June 1–2, 1941—the Farhud. Over two days of pogrom, attackers killed scores (contemporary counts vary, commonly around 180–200 dead) and injured hundreds, before order was restored. The Farhud engraved the war onto Iraq's social fabric and foreshadowed the postwar unravelling of one of the Middle East's oldest Jewish communities.
From frontline to logistics hub
From late 1941, the theater's role flipped from firefight to logistics hub. British forces reorganized as Persia & Iraq Command (PAI Force) to secure oil installations and run the Persian Corridor—moving Lend-Lease supplies from Gulf ports through Iraq and Iran to the USSR. Indian Army formations, RAF units, and locally raised forces garrisoned bases and railheads while American troops and transport expertise joined from 1942. Strategically, Iraq became a quiet hinge of the Allied war economy rather than a frontline battlefield.
Bottom line
In 1941, Iraqi nationalism collided with treaty-bound imperial power, drawing in German and Italian help that proved too small and late to change the outcome. The war in Iraq left three legacies: a cautionary tale about sovereignty constrained by treaties; a searing memory in the Farhud; and a transformed map of Allied logistics that ran, quite literally, through Basra, Habbaniya, and up the road to Persia.