Quite a few Marines served in the ETO. Some Marines even served in the OSS in Europe during WWII: Sterling Hayden, Robert H. Barrow, Peter Ortiz, etc.
Assigned to the secretive world of spies and saboteurs were 51 Marines who served with the U.S. Office of Strategic Services to engage in behind-the-lines operations in North Africa and Europe from 1941 to 1945. These OSS Marines served with partisan and resistance groups in France, Germany, Yugoslavia, Italy, Austria, Albania, Greece, Morocco and Egypt; on the islands of Corsica and Sardinia; in Rumania; and in North and West Africa. Ten of these OSS Marines also served with forces in Ceylon, Burma, Malaya and China. Marine Colonel Peter J. Ortiz was twice awarded the Navy Cross for heroism while serving with the French Resistance.