President Obama reminds us today that when U.S., British and Canadian forces trudged into bullets and mortar shells on the beaches of Normandy 65 years ago, their success was not assured. We've seen the movie and know the ending: John Wayne and Tom Hanks won the war, along with our plucky allies, David Niven and Michael Caine.
But the young soldiers of 1944, now gone or grown old, faced forbidding shores, bristling with steel. They had no exit strategy. They could only win, or die trying.
In recent years, several books have questioned whether that war was wise. They range from the right, with Pat Buchanan's Churchill, Hitler and the "Unnecessary War", to the left, with Nicholson Baker's Human Smoke.
Several years ago, we asked John Keegan, the British military historian, what he thought might have happened if the D-Day invasion had failed.
"The Allies would have tried it again," he said. But the next time, they would lack any advantage of surprise. Germany's V-2 missiles, which could not be stopped by planes or anti-aircraft fire, became operational that summer, and could have decimated Allied soldiers and sailors even before they left port.
Keegan said Churchill's government in Britain would have fallen, and a new one would have sued for peace. Franklin Roosevelt would not have run for re-election, and someone who had favored accommodation with Germany — a Charles Lindbergh, as Phillip Roth once imagined, or Joseph P. Kennedy — might have been elected in America. Without U.S. and British assistance, the Soviet Union would have collapsed.
"America would be marooned," said Keegan, sweeping a hand over a globe. "Alone on a vast planet flooded by fascism."
Hitler might have let America alone for a while, he said. But every Jew in Europe, every Roma, every gay, Jehovah's Witness, disabled or retarded person, and millions more Poles and Russians would have been executed or worked to death.
How many millions would we allow to be killed, he asked, so that Americans could live in an isolation some would call peace? And what kind of hell would be left to our children in a world dominated by the creators of the Nuremberg Laws and death camps?
New histories can usefully examine the terrible moral bargains America and Britain made to prevail, from the firebombings of cities, to making an ally of Joseph Stalin, who shared Hitler's immoral makeup.
But on some anniversaries, it seems right to remind ourselves that most of us alive in America today have grown up free to try on whatever ideas we like, like hats in a store window, because of the suffering, blood and sacrifice of men and women now passing into history