In February 1941, Murphy negotiated the Murphy-Weygand Agreement, which allowed the United States to export to French North Africa in spite of the British blockade and trade restrictions against the Vichy-governed area. In autumn of 1942, at President Franklin Roosevelt's behest, Murphy investigated conditions in French North Africa in preparation for the Allied landings, Operation Torch, the first major Western Allied ground offensive during World War II. He was appointed the President's personal representative with the rank of Minister to French North Africa. Murphy made contact with various French army officers in Algiers and recruited them to support the Allies when the invasion of French North Africa came. During this time, Kenneth Pendar served as his second. Prior to the November 8 invasion, Murphy, along with U.S. General Mark W. Clark, had worked to gain the cooperation of French General Henri Giraud for the attack. The Americans and British hoped to place Giraud in charge of all French forces in North Africa and command them for the Allied cause. Giraud, however, mistakenly believed that he was to assume command of all Allied forces in North Africa, which put Murphy's diplomatic skills to the test to keep Giraud on board. Murphy and Clark jointly convinced the French in North Africa to accept Admiral François Darlan, the commander of all French military Forces loyal to the Vichy regime and coincidentally in Algiers, as the highest authority in French North Africa and Giraud as Commander of all French military in North Africa. Murphy used his friendly contacts with the French in North Africa to gain their co-operation in re-entering the war against the Axis. He also needed all his diplomatic skills to steer Clark away from confrontation with the French, especially Darlan. When Darlan was assassinated in late December, an irritant to good relations was removed. Keeping the French united and aligned with the Allies into 1943 taxed Murphy's skills to their limit. He gained a powerful ally in British politician Harold Macmillan, also posted to Algiers in January 1943. The two diplomats worked together amiably to ensure that the Casablanca Conference went smoothly in January 1943 and that Giraud and de Gaulle would join forces to unite the French among the Allies. Keeping the quarrelsome French united and working with the Americans and British exasperated and exhausted Murphy. When Eisenhower needed a civilian from the State Department to assume a similar role in Italy in 1943, Murphy gladly accepted it and left Algiers behind.
Murphy retired from the State Department in December 1959 but became an adviser to Presidents John F. Kennedy, Lyndon B. Johnson, and Richard Nixon. He served on President Gerald Ford's Foreign Intelligence Advisory Board. He was a member of the Steering Committee of the Bilderberg Group. In 2006, Murphy was featured on a United States postage stamp, one of a block of six featuring prominent diplomats.
