From October 1942 to early 1944, brevetted first to Colonel and then to Brigadier, he headed the SOE-controlled British Military Mission to occupied Greece. In this capacity, he was directly involved in the coordination of the rival ELAS and EDES partisan groups for the destruction of the Gorgopotamos viaduct in November 1942 (Operation Harling), and for the British destruction of the Asopos railway bridge on 21 June 1943 as part of Operation Animals. Increasingly drawn into the brewing conflict between the Communist-dominated ELAS and the republican EDES, as well as into British designs to restore the unpopular Greek monarchy postwar, Myers was criticised by the Foreign Office for what they believed to be favourable treatment towards ELAS and he was removed from his post. He was succeeded as head of the British mission by his deputy, Chris "Monty" Woodhouse.