Although George C. Marshall served as US Secretary of State for only two years (from January 1947 to January 1949), he was responsible during that brief time period for the most important peacetime transatlantic initiatives in American history – most notably the European Recovery Programme that bears his name and the North Atlantic Treaty Organisation (NATO) whose formation would be completed a few months after he left office. While these initiatives clearly resulted from the growing Soviet–American conflict after the Second World War and the ensuing cold war, their roots lay in the strong transatlantic policies and strategies in which Marshall had participated, and which he had often initiated, during the Second World War. What follows is an analysis of those wartime policies and strategies, and their relationship to the postwar transatlantic policies and strategies Marshall championed as Secretary of State.