Juin studied and taught at the École Supérieure de la Guerre (1919–1921, 1933–1935). He also attended the Higher Command Course in Paris (1938–1939), but he spent most of the interwar period with the French North African Army in staff assignments, participating in pacification campaigns. By 1935, he had risen to colonel and commanded a regiment in Algeria.
In December 1939, Juin took command of the 15th Mortorized Infantry Division in France. From 10 to 29 May 1940, in the Battle for France, he and his troops performed well in Belgium and northern France, covering the Allied retreat to Dunkerque and helping to make possible the evacuation there. On 30 May, German troops captured Juin; at the insistence of General Maxime Weygand, he was repatriated in June 1941. Sent by the Vichy government as a major general to North Africa, he commanded French troops in Morocco and, from November as lieutenant general and then general, French troops in Algeria and Tunisia as well. Juin worked to build up his forces so that they could defend North Africa against any invader. He had no advance knowledge of the Anglo-American North African landings (Operation torch) in November 1942, but later that month, he was instrumental in persuading Admiral Jean Darlan to order a cease-fire.
Briefly heading the French army detachment on the Tunisia Front (1942–1943), Juin was soon occupied with the preparation of the French Expeditionary Corps (CEF), which deployed to Italy in November 1943. To command this corps, he accepted a voluntary reduction in rank to lieutenant general. In Italy, he established a good working relationship with the U.S. Fifth Army's temperamentally difficult commander, Lieutenant General Mark W. Clark. Juin convinced Clark and his superior, British General Sir Harold Alexander, to take advantage of his colonial North African troops' expertise in mountain warfare. The CEF displayed its mettle from January 1944 and played a decisive role in the Allied breakthrough of the German Gustav Line to Rome in May. Outflanking the Germans in the Apennines, the CEF enabled the Allied capture of Monte Cassino in May 1944 and Siena and Florence that July. Juin was arguably the ablest Allied commander in the 1943–1945 Italian Campaign.
In 1944, Juin favored reinforcing Allied troops in Italy, but General Charles de Gaulle, head of the Fighting French government-in-exile, insisted on French participation in the scheduled Allied landings in southern France and ordered Juin to relinquish his troops to General Jean de Lattre de Tassigny for that purpose. De Gaulle later wrote that de Lattre was better suited than the colonial Juin to lead soldiers in metropolitan France, but there has been speculation that he preferred that no single general except himself emerge from the war as France's principal military hero.
Juin served as chief of the French defense staff (1944–1947), resident general in Morocco (1947–1951), inspector general of the armed forces (1951), and commander of the North Atlantic Treaty Organization (NATO) land forces in Central Europe (1951–1956). Made a marshal of France in 1952, Juin outspokenly opposed Algerian nationalism and was embittered by de Gaulle's decision to grant Algerian independence in 1962. He died in Paris on 27 January 1967. Priscilla Roberts and Richard G. Stone
Clayton, Anthony. Three Marshals of France: Leadership after Trauma. London: Brassey's, 1992.; Crémieux-Brilhac, Jean-Louis. Les Français de l'an 40. 2 vols. Paris: Gallimard, 1990.; de Gaulle, Charles. The Complete War Memoirs of Charles de Gaulle. 1955–1959. New York: Carroll and Graf, 1998.; Goutard, Adolphe. "Marshal Alphonse Juin." In Michael Carver, ed., The War Lords: Military Commanders of the Twentieth Century, 596–611. Boston: Little, Brown, 1976.; Horne, Alistair. To Lose a Battle: France, 1940. Boston: Little, Brown, 1969.; Ordioni, Pierre. Tout commence à Alger, 1940–1945. Paris: Éditions Albatros, 1985.
Priscilla Roberts and Richard G. Stone