After her refit, "Falmouth" returned to duties in the Gulf. On 3–4 April 1941, Rashid Ali al-Gaylani, the former Iraqi Prime Minister, launched a coup d'état, seizing power in Iraq and threatening British interests in Iraq, including the large airbase at RAF Habbaniya. In response, a convoy that was about to set out from Karachi for Malaya carrying a brigade of Indian troops was diverted to Basra in Iraq, with orders to occupy the Basra area, ensuring a base of operations if required. "Falmouth" formed part of the escort for the convoy, which arrived at Basra on 18 April, helping to lead the ships of the convoy along the Shatt al-Arab. The landings were not opposed by the Iraqis. "Falmouth" escorted more convoys to Basra as the British built up their forces in preparation for the Anglo-Iraqi War. On 25 August 1941 Britain and the Soviet Union invaded Iran, with "Falmouth" in charge of the landings at Khorramshahr, carrying two companies of the 3/10th Baluch Regiment. She ran aground when leaving Basra, and the Australian sloop continued on without "Falmouth" to ensure that Iranian naval forces at Khorramshahr did not interfere, sinking the Iranian sloop and capturing two Iranian gunboats. "Yarra" then waited for "Falmouth" to arrive before the two ships landed their troops. In October 1941, "Falmouth" was sent to Suez, returning to Ceylon after the Japanese invasion of Malaya in December 1941.