Like many other world-changing events, the successful Allied assault on Nazi-occupied France that began 60 years ago today has assumed over the years a sense of near inevitability, as though no other outcome were imaginable. That wasn't a conviction shared by its authors, least of all Supreme Allied Commander Dwight D. Eisenhower. The night before the invasion, he drafted a message reading in part: "Our landings in the Cherbourg-Havre area have failed to gain a satisfactory foothold and I have withdrawn the troops . . . If any blame or fault attaches to the attempt it is mine alone."

The cold-blooded recognition of war's precariousness underlying Ike's readiness to confront the possibility of failure is a quality one doesn't always find in military commanders and finds even less often in their political masters. In part, that's because it isn't a quality we spend a lot of time inculcating. For many reasons, some sound and others less so, the processes that bring political and military leaders to the forefront tend too often to suppress acknowledgment of war's contingency and the self-doubt to which some fear it might contribute.

To some extent, reluctance to contemplate the possibility of failure reflects the national character. It has been argued that, as a people, we lack a sense of tragedy. Insulated for most of our brief history by two great oceans and blessed with material abundance, we tend to expect success in great endeavors as a matter of course.

In no respect is that more true than in respect to war. After all, we haven't been invaded since 1815. On this con- tinent, the last major war ended in 1865. Abroad, apart from Vietnam, the effects of which still linger, we've enjoyed a virtually unbroken record of military success.

Of course, any soldier or statesman with a sense of history knows that war differs from other human enterprises above all in its unpredictability. That uncertainty reflects war's intrinsic friction as well as the malevolence, ingenuity and occasional perversity of the enemy. But recognizing it abstractly is one thing. Accepting its implications is another.

For military commanders, in whom the appearance of confidence can be even more important than its reality, acknowledging uncertainty is especially problematic. The handmaiden of uncertainty is hesitation, and in war hesitation rarely is desirable.

The only real antidote to uncertainty is action. In war, even more than in other great enterprises, that almost always requires taking risks. The difference between risk-taking and gambling, however, turns finally on the commander's willingness to confront frankly the possibility of failure.

Eisenhower understood that hard necessity perfectly. Operation Overlord was an enormously risky undertaking. Failure might have irrevocably altered the outcome of the war and certainly would have prolonged it. A less courageous commander might have been paralyzed by the risks. A less sensible one might simply have discounted them.

Eisenhower did neither. Instead, having made every effort that forethought, skill and attention to detail could to diminish the risks facing his troops, Ike made the decision to go. Then, recognizing that all those efforts still couldn't guarantee success, he set about preparing himself and if necessary his countrymen for failure. That he could look the latter possibility squarely in the face was the ultimate proof of his fitness for the job.

So, too, his readiness to accept personal responsibility for a failure that, in the end, Allied blood and courage prevented. It was a quality he shared with another great American soldier. Meeting George Pickett's shattered remnants as they withdrew from Cemetery Ridge on Gettysburg's last day, Robert E. Lee told them, "It was my fault. It was all my fault."

No soldier wants to go into battle on the orders of a hesitant commander, nor a nation on those of an irresolute leader. Self-confidence thus is an essential quality of soldiers and statesmen alike.

But in war above all, there's a fine line between self-confidence and hubris. Today, as we honor those who made Ike's premature acknowledgment of defeat unnecessary, that distinction is worth remembering.

Richard Hart Sinnreich writes on military affairs for the Lawton (Okla.) Sunday Constitution.