Morale

An addition to the point I made in the previous post.
Similar to the idea that we are winning but can't convince the public, and that that is our only barrier to victory is the idea that negative news coverage demoralizes our troops and so makes defeat more likely.
This strikes me as akin to the idea that Bush is to blame for the economic downturn of 2001 because he was "talking down" the economy (he was theoretically doing this because he was scared that there would be a downturn when he got into office, and didn't want to be blamed for it). By this I mean that it is sheer nonsense based on the "power over truth" philosophy that we can alter fundamental reality by willing it to be different (I believe that this ideology is associated with Michel Foucault.
The economy, I believe, functions mainly based on the wisdom of the overall decisions made by the people who are most in charge of its structure, e.g. bankers, stockbrokers, businessmen. Consumer confidence and emotion have very little impact, because the people with real power are those who do not make stupid decisions from day to day based on any one person's statements. There are the basics of what constitute good decisions that do not change much or do not change quickly. People's "feelings" will not alter these. If banking is sound, scare-mongering will not cause a depression. the idea that anyone can "talk up" or "talk down" the economy so as to have any lasting effect is ridiculous. Maybe "talking down" the economy will cause stocks to drop for a day or two, but within a week things will be back to reflecting the underlying reality.
The same is true in war. If the overlying strategy is sound, things will go well regardless of the amount of carping at home. If it is unsound, things will go poorly. Morale plays a role, and feelings on the homefront play some role, but in the end the reasonableness of the strategy, the wisdom of the tactics, and the sufficiency of the hardware.