At that time, the pro-German government of Iraq led by Rashid Ali al-Kaylani had tried to capture the RAF base at Habbaniya and force the British to leave the country. During the short Anglo-Iraqi War, Quinan's invasion from the south, supported by British troops from Trans-Jordan overthrew the Axis-leaning Iraqi government and replaced it with a pro-British one. He became GOC 10th Army in Persia and Iraq Command. As the Luftwaffe had used bases in Syria to support the Iraqis, an operation was planned to invade Syria from Palestine, supported by Quinan's troops in Iraq and replace the Vichy French government of Syria and Lebanon with a Free French one. This was completed successfully. Later in 1941, he planned and executed the invasion of Persia. The principal reason for this was to secure the supply lines to the Soviet Union and to protect British oil installations in Abadan.