Sometimes the failure seems due more to carelessness than to cowardice; Napoleon's disastrous underestimate of the difficulties of his projected Russian campaign seems more due to carelessness than to cowardice; but this may be due to a difficulty of associating cowardice with Napoleon.
But is it not equally difficult to associate carelessness with Napoleon?
What professional calculator, what lawyer's clerk was ever more careful than Napoleon was, when dealing with problems of war?
Who was ever more attentive to details, who more industrious, who more untiring?
And yet Napoleon's plans for his Russian campaign were inadequate to an amazing degree, and the inadequacy was the cause of his disaster.

But whether the cause was carelessness or moral cowardice on his part, the fact remains that he did not estimate the situation with sufficient care, and make due plans to meet it.
This unwillingness to look a difficult situation in the face one can see frequently in daily life.

Great difficulties seem to appall some people.

They hate so much to believe a disaster possible, they fear so much to let themselves or others realize that a danger is impending, they are so afraid that other people will think them "nervous," and they shrink so from recommending measures that would cause great exertions or great expenditures, that they are very prone to believe and say that there is no especial danger, and that whatever danger there may be, can be obviated by measures that are easy and cheap to carry out.
If we yield to this feeling, we are guilty of moral cowardice, and we vitiate all the results of all our labors.

We _must_ make a correct estimate of the situation--or rather we must estimate the situation to be as grave as it is--or our preparations will be of no avail.