June 4, 2007, marked the 65th anniversary of the Battle of Midway, the pivot of World War II in the Pacific. A quarter-century later, on June 5, 1967, the Israeli Air Force destroyed its Egyptian counterpart in one lightning blow, thus making possible an Israeli victory in the Six-Day War --- the event that set the stage for the past 40 years of Middle Eastern history. Both anniversaries offer important moral lessons to ponder.

A new book by Jonathan Parshall and Anthony Tully, "Shattered Sword," offers an engagingly (if sometimes excessively) revisionist history of Midway. Against the conventional telling of this tale --- in which sharp-eyed American signals intelligence, the strategic and tactical acumen of Admiral Raymond Spruance, the dithering of Admiral Chuichi Nagumo, and the heroic self-sacrifice of three U.S. Navy torpedo squadrons --- were the key factors in the battle, Parshall and Tully emphasize the ways in which Japanese technical, strategic and command incapacities played a large role in the destruction of four enemy aircraft carriers by U.S. Navy Dauntless dive-bombers, a blow from which the Japanese Navy never recovered. The conventional story of the American David taking down the hitherto invincible Japanese Goliath is not-quite-right, our authors suggest.

Yet there is something to be remembered, on this anniversary, from the conventional account of Midway --- and it's the image of those three American torpedo squadrons from Hornet, Enterprise and Yorktown, flying obsolete Douglas Devastators, boring in on their targets, being shot down one by one by Japanese Zeros --- and so disrupting Japanese flight operations on the (unscathed) target carriers that the subsequent dive-bomber attacks of the Dauntlesses could change the course of history in two engagements lasting perhaps ten minutes each.

The lesson? If freedom is not free, and it isn't, then free peoples will always have to raise up men capable of stretching courage to its outer limits, often paying the ultimate price in the process. Few Americans, today, remember the names of the squadron commanders of Torpedo Three (Lt. Cdr. Lem Massey), Torpedo Six (Lt. Cdr. Gene Lindsey), and Torpedo Eight (Lt. Cdr. John Waldron). But we should, and we should recall their names, and those of their squadron-mates, with reverent gratitude.

Twenty-five years later, as Michael Oren narrates in "Six Days of War," the State of Israel was in dire peril. Egypt had imposed a blockade of Israel's only outlet to the south, the port of Eilat. A Soviet disinformation campaign falsely claimed that Israel was massing troops on the Syrian border, preparing an attack --- even as Egypt (having thrown U.N. peacekeepers out) was remilitarizing the Sinai and concluding a military pact with Jordan, thus surrounding Israel.

Seven other Arab states began sending troops to Egypt, Syria and Jordan, anticipating a vast slaughter of Jews and the State of Israel being driven into the sea, and out of existence. The U.N. was, as usual, useless, and President Lyndon Johnson's efforts to raise an international task force to open a passage to Eilat failed.

Alone, Israel took the hard decision to strike first --- to crush the Egyptian air force in one blow, and thus make possible an effective defense against the ground attack that was certainly coming. The Israelis begged Jordan's King Hussein to stay out of the fight; but Hussein, perhaps deceived by Egypt's Gamal Abdel Nasser, got in --- and lost the West Bank. In consequence, Jerusalem was united under a Jewish flag for the first time in two millennia. Much would flow from Jordan's loss of the West Bank, including, alas, much blood.

The lesson? Sometimes, it is morally imperative to shoot first --- not just strategically wise or tactically advantageous, but morally imperative. Even given the military gamble involved, for the Israeli government not to have ordered a preemptive attack on the Egyptian air force to even the odds on national survival would have been an act of moral irresponsibility.

That correct just-war decision ought to be remembered, not because it provides a universal template, but because it makes a crucial moral point: faced with certain aggression, responsible public authorities need not wait for the aggressor's first blow to fall.

George Weigel is a senior fellow of the Ethics and Public Policy Center in Washington, D.C.