A kaleidoscopic pop history--not bad, not good--centering on the eight months of French and British inaction (despite a nominal declaration of war) between the Nazi invasion of Poland, in September 1939, and the German assault on the West, in May 1940. In August of '39, the Nazi-Soviet Pact had freed Hitler to attack Poland with impunity--because the British and French, in guaranteeing Poland's security, had expected the Soviets to do the fighting. Stalin, knowing this--and miffed because they sent flunkies to court him, while Hitler sent Ribbentrop, with concessions--gained deeper borders (the eastern half of Poland) and additional time by signing with the Nazis. So Hitler's attack on Poland found the Allies unprepared and disinclined to fight: the British had a miniscule army and were loathe to use their bombers for fear of retaliation; the French thought they had the Maginot Line. All this, though long known to historians, has never quite entered the public consciousness, so strong was the reaction, in '39, against Stalin's supposed treachery. In that sense, then, Shachtman (The Day America Crashed, Edith and Woodrow) performs a service: cutting from principal to principal, splicing in eyewitness experiences, piling detail upon detail, he achieves an approximation of events (the Russo-Finnish Winter War, the seizure of Denmark and Norway, the invasion of Holland and Belgium) through the fall of France. Some of the detailing is tacky, irrelevant, even witless (""The cabinet room at 10 Downing Street was in that part of the house first inhabited by an illegitimate daughter of Charles II""--as, indeed, who wasn't); some of the key sources (especially, David Irving on Hitler) are not exactly top-drawer; some of the splintering is sheer hyperactivity. But counterpoised to Allied dithering are distressed quotes from anti-Nazi Germans (""Why don't they, too, cross some river or other. . . ?"") and evidence of known SS excesses in Poland, known terrorism against the Jews. In his foreword, Shachtman grabs at relevance by calling 1939-40 ""a period of repressed but subtly violent cold war."" Politically, the comparison is facile; but military historians do maintain that the Nazis could have been wiped out in '39 by British bombers and the French army. So the question of who gored whose ox (and who suffered) transcends the historical hype.