Two years after publishing a remarkable book on France's "dark years" (1940-44), Jackson returns to the historians' battlefield with an investigation of the fall of France in May-June 1940, which he covered much more briefly in the earlier volume. Jackson's account is vivid, particularly sharp and sound in examining the deteriorating relations between France and its often condescending British ally and the increasingly bitter rivalries within the French leadership. There are (at least) three explanations for France's catastrophic defeat. One attributes the loss to crucial mistakes in French strategy. The second emphasizes the battle fatigue that gripped both a sclerotic high command and a deeply pacifist nation exhausted by World War I. And the third focuses on French "decadence" (the title of Jean-Baptiste Duroselle's magisterial book) in the interwar period. Jackson, once again fair and judicious, puts his main emphasis on the military aspects of the defeat: intelligence failure (already emphasized by Ernest May in his Strange Victory), the terrible communications system, and the simultaneously centralized and divided command structure. He also validates much of what the second school has stressed, especially the demoralizing effect of the "phony war" that preceded the Nazi assault, but does not give much credit to the third. His conclusions are reinforced by some intriguing analysis -- e.g., on what distinguished 1940 from 1914 and what were Germany's strengths ("The greatest German weapon was ... surprise") -- and an ingenious study of counterfactuals -- e.g., what would have happened had the United Kingdom been in France's place? The final chapter focuses on the enormous impact of the fall on the French outlook since 1940, and on the birth and long life of the Gaullist vision. Did de Gaulle draw "quite inappropriate conclusions" from 1940, refusing to "accept the geopolitical realities underlying France's decline," or did he inspire France's "capacity for survival and reinvention"? Jackson ends by quoting Chou En-lai's famous answer to a question about the effects of the French Revolution: "It is too early to tell."