The Dark Side of the Island - Jack Higgins

The Greek islands, sun-drenched and tranquil, evoke pictures from a tourist brochure. It takes a special imagination to dredge their blood-soaked history when, as a subject land in WW II, island revolts were crushed by the occupying Germans.
In those days, Hugh Lomax was sent by the British to aid the Greeks in their struggle. He succeeded brilliantly, but on leaving for another assignment was betrayed. Those who collaborated with him were executed and survivors, not unnaturally, held Lomax responsible for the carnage.