A new France emerged from World War I as the continent's dominant power. But four years of hostile occupation had reduced northeast France to ruins. Beginning in 1919, French foreign policy aimed at keeping Germany weak through a system of alliances, but it failed to halt the rise of Adolf Hitler and the Nazi war machine. On May 10, 1940, Nazi troops attacked, and, as they approached Paris, Italy joined with Germany. The Germans marched into an undefended Paris and Marshal Henri Philippe Pétain signed an armistice on June 22. France was split into an occupied north and an unoccupied south, Vichy France, which became a totalitarian German puppet state with Pétain as its chief. Allied armies liberated France in Aug. 1944, and a provisional government in Paris headed by Gen. Charles de Gaulle was established. The Fourth Republic was born on Dec. 24, 1946. The empire became the French Union; the national assembly was strengthened and the presidency weakened; and France joined NATO. A war against Communist insurgents in French Indochina, now Vietnam, was abandoned after the defeat of French forces at Dien Bien Phu in 1954. A new rebellion in Algeria threatened a military coup, and on June 1, 1958, the assembly invited de Gaulle to return as premier with extraordinary powers. He drafted a new constitution for a Fifth Republic, adopted on September 28, which strengthened the presidency and reduced legislative power. He was elected president on Dec. 21, 1958.
France next turned its attention to decolonialization in Africa; the French protectorates of Morocco and Tunisia had received independence in 1956. French West Africa was partitioned and the new nations were granted independence in 1960. Algeria, after a long civil war, finally became independent in 1962. Relations with most of the former colonies remained amicable. De Gaulle took France out of the NATO military command in 1967 and expelled all foreign-controlled troops from the country. De Gaulle's government was weakened by massive protests in May 1968 when student rallies became violent and millions of factory workers engaged in wildcat strikes across France. After normalcy was reestablished in 1969, de Gaulle's successor, Georges Pompidou, modified Gaullist policies to include a classical laissez-faire attitude toward domestic economic affairs. The conservative, pro-business climate contributed to the election of Valéry Giscard d'Estaing as president in 1974.
Socialist François Mitterrand attained a stunning victory in the May 10, 1981, presidential election. The victors immediately moved to carry out campaign pledges to nationalize major industries, halt nuclear testing, suspend nuclear power-plant construction, and impose new taxes on the rich. The Socialists' policies during Mitterrand's first two years created a 12% inflation rate, a huge trade deficit, and devaluations of the franc. In March 1986, a center-right coalition led by Jacques Chirac won a slim majority in legislative elections. Chirac became prime minister, initiating a period of “cohabitation” between him and the Socialist president, Mitterrand. Mitterrand's decisive reelection in 1988 led to Chirac being replaced as prime minister by Michel Rocard, a Socialist. Relations, however, cooled with Rocard, and in May 1991 Edith Cresson—also a Socialist—became France's first female prime minister. But Cresson's unpopularity forced Mitterrand to replace Cresson with a more well-liked Socialist, Pierre Bérégovoy, who eventually was embroiled in a scandal and committed suicide. Mitterrand did succeed in helping to draft the Maastricht Treaty and, after winning a slim victory in a referendum, confirming close economic and security ties between France and the European Union (EU).
On his third try Chirac won the presidency in May 1995, campaigning vigorously on a platform to reduce unemployment. Elections for the national assembly in 1997 gave the Socialist coalition a majority. Shortly after becoming president, Chirac resumed France's nuclear testing in the South Pacific, despite widespread international protests as well as rioting in the countries affected by it. Socialist leader Lionel Jospin became prime minister in 1997. In the spring of 1999, the country took part in the NATO air strikes in Kosovo, despite some internal opposition.