Meanwhile, Hitler’s accession had placed French governments in an increasingly grave foreign-policy dilemma. By 1934 many French leaders believed that a return of “Poincarism” was in order, and Doumergue’s foreign minister, Louis Barthou, set out to reinforce and extend France’s alliance system. He reaffirmed French ties with Poland and the “Little Entente” countries and sought new understandings with both Italy and the Soviet Union. Barthou’s assassination in late 1934 weakened the new alliance policy, though Laval in 1935 paid visits to both Rome and Moscow and actually signed a mutual assistance treaty with the U.S.S.R.

Mussolini’s invasion of Ethiopia in late 1935 and Hitler’s military reoccupation of the Rhineland in March 1936 were serious blows to French policy. After consulting the British, the French cabinet decided not to risk a confrontation with Hitler, who thus won a major diplomatic victory. Hitler promptly fortified the Rhine frontier, so that French guarantees of military aid to eastern European allies lost much credibility. Furthermore, Hitler and Mussolini joined forces against the status quo powers. With Italy lost, Frenchmen of the centre and right grew cool toward closer ties with the Soviet Union; they had counted on Italy to counterbalance Soviet influence. France found itself dangerously isolated, dependent on the small eastern European countries and on the uncertain prospect of British military support in crisis. Not surprisingly, French policy after 1936 showed signs of weakness and drift.

The outbreak of the Spanish Civil War in July 1936 posed a severe problem of conscience for Blum’s Popular Front government: whether to send aid to the Spanish republic, the only other Popular Front regime in Europe. Reluctantly, Blum remained aloof; his Radical allies strongly opposed intervention and threatened to bring down the cabinet.

A new crisis developed in March 1938, when Hitler’s troops for the first time crossed a frontier—into Austria. The French and British confined themselves to formal protests. German pressure on Czechoslovakia followed. Although France was formally committed to aid Czechoslovakia in case of aggression, Premier Daladier succumbed to British pressure to appease Hitler by a compromise settlement. The Munich Agreement of September 30 provided a breathing space but caused sharp dissension and self-doubt in France. When Hitler occupied what was left of Czechoslovakia in March 1939, it appeared to be too late for successful diplomatic or military resistance to Hitler, yet a failure to resist would hand over the Continent to German domination. From April until August the French and British sought to bring the Soviet Union into a joint pact against Hitler, with the French pressing the reluctant British to take the risks involved. A Soviet decision to break off negotiations and to sign a pact with Hitler instead was the last in a long chain of disasters for France. On September 3, two days after Germany invaded Poland, the French and British governments reluctantly declared war on Germany.

French and British attempts to aid the Poles would have been ineffective even if tried. Hitler’s offer of peace immediately after Poland fell was rejected by the Western Allies. The German armies smashed through the Netherlands and Belgium on May 10, 1940, and soon broke the French defensive lines near Sedan. The German blitz brought chaos all along the Allied front. In Paris, Premier Paul Reynaud (who had replaced Daladier in March) pleaded for emergency aid from Britain and the United States; the British sent some additional air units but were unwilling to denude their island of all air defense; U.S. President Franklin D. Roosevelt offered moral encouragement but not open intervention.

On June 10, with the Germans approaching Paris, the government departed for Tours and declared Paris an open city. British Prime Minister Winston Churchill twice flew to Tours in an effort to keep France in the war. But Reynaud, who favoured continued resistance (from North Africa, if necessary), rapidly lost ground to the defeatists in his cabinet, headed by Pétain. On June 14 the cabinet left Tours for Bordeaux. Churchill, in a last desperate effort, proposed a pact of “indissoluble union” that would merge France and Britain as a single nation. By the time the proposal reached Bordeaux on June 16, however, the Pétain faction had gained control of the cabinet. Reynaud resigned that evening; Pétain was appointed in his place and asked Germany for surrender terms. On June 22 an armistice was signed with the Germans, near Compiègne, in the same railway car that had been the scene of Foch’s triumph in 1918. The armistice provided for the maintenance of a quasi-sovereign French state and for the division of the country into an occupied zone (northern France plus the western coast) and an unoccupied southern zone. France was made responsible for the German army’s occupation costs. The French army was reduced to 100,000 men and the navy disarmed in its home ports.