 Macmillan built a rapport with US General Dwight D. Eisenhower, then Supreme Allied Commander in the Mediterranean (SACMED), which proved helpful in his career, and Richard Crossman later recalled that Macmillan's "Greeks in the Roman Empire" metaphor dated from this time (i.e.that as the US replaced Britain as the world's leading power, British politicians and diplomats should aim to guide her in the same way that Greek slaves and freedmen had advised powerful Romans).At the Casablanca Conference Macmillan helped to secure US acceptance, if not recognition, of the Free French leader Charles de Gaulle.