We all share the guilt. We went along with everything, and we half-took the Nazis seriously instead of saying "to hell with you and your stupid nonsense". I misled my soldiers into believing this rubbish. I feel utterly ashamed of myself. Perhaps we bear even more guilt than these uneducated animals.

When assessing the responsibility for this war—we have to confess honestly that we bear a share of the guilt. If I said this thought oppresses me, I would say too little—this thought never leaves me. I live in it.

The greatest sources of our suffering are the lies we tell ourselves.

Every war, every crime against humanity among the damned of the Earth is supposed to be somewhat our fault and ought to lead us to confess our guilt, to pay endlessly for being a member of the bloc of wealthy nations.

We are all so guilty at the way we have allowed the world around us to become more ugly and tasteless every year that we surrender to terror and steep ourselves in it.

I don't believe that the big men, the politicians and the capitalists alone, are guilty of the war. Oh no, the little man is just as guilty, otherwise the peoples of the world would have risen in revolt long ago! There's in people simply an urge to destroy, an urge to kill, to murder and rage, and until all mankind, without exception, undergoes a great change, great wars will be waged, everything that has been built up, cultivated, and grown will be destroyed and disfigured, after which mankind will have to begin all over again.

Who am I to blame for all this? ...The guilty one is the crazy person who decided to begin a war when all may not have been done to avoid it.

…we all lie to ourselves; we tell our own selves more lies than we ever do other people.

Very often in a conflict, we believe the problem is the other person or group. We think it is all their fault and that if they would just stop doing what they are doing or being the way they are, we would have peace and happiness. So we may be motivated by the desire to destroy the other side. We may wish they didn’t exist. But looking deeply, we know that we are not the only ones who have suffered — they have also suffered. When we take time to calm ourselves down and look deeply into the situation, we can see that we are co-responsible, that we have co-created the conflict by our way of thinking, acting, or speaking, either individually or as a group or nation.

Twenty years ago, Dwight Macdonald published a series of articles in Politics on the responsibility of peoples and, specifically, the responsibility of intellectuals. I read them as an undergraduate, in the years just after the war, and had occasion to read them again a few months ago. They seem to me to have lost none of their power or persuasiveness. Macdonald is concerned with the question of war guilt . He asks the question: To what extent were the German or Japanese people responsible for the atrocities committed by their governments? And, quite properly, he turns the question back to us: To what extent are the British or American people responsible for the vicious terror bombings of civilians, perfected as a technique of warfare by the Western democracies and reaching their culmination in Hiroshima and Nagasaki, surely among the most unspeakable crimes in history.

Under the influence of politicians, masses of people tend to ascribe the responsibility for wars to those who wield power at any given time. In World War I it was the munitions industrialists; in World War II it was the psychopathic generals who were said to be guilty. This is passing the buck. The responsibility for war falls solely upon the shoulders of these same masses of people, for they have all the necessary means to avert war in their own hands. In part by their apathy, in part by their passivity, and in part actively, these masses of people make possible the catastrophes under which they themselves suffer more than anybody else. To stress this guilt on the part of masses of people, to hold them solely responsible, means to take them seriously. On the other hand, to commiserate masses of people as victims, means to treat them as small, helpless children. The former is the attitude held by genuine freedom-fighters; the latter the attitude held by the power-thirsty politicians.

Many veterans feel guilty because they lived while others died. Some feel ashamed because they didn’t bring all their men home and wonder what they could have done differently to save them. When they get home they wonder if there’s something wrong with them because they find war repugnant but also thrilling. They hate it and miss it.Many of their self-judgments go to extremes. A comrade died because he stepped on an improvised explosive device and his commander feels unrelenting guilt because he didn’t go down a different street. Insurgents used women and children as shields, and soldiers and Marines feel a totalistic black stain on themselves because of an innocent child’s face, killed in the firefight. The self-condemnation can be crippling.
The Moral Injury, New York Times. Feb 17, 2015

We often behave in ways that are guaranteed to make us unhappy. Many of us spend our lives marching with open eyes toward remorse, regret, guilt, and disappointment.And nowhere do our injuries seem more casually self-inflicted, or the suffering we create more disproportionate to the needs of the moment, than in the lies we tell to other human beings. Lying is the royal road to chaos.

This war torments me. Again and again I ask if it could have been avoided and what I should have done differently. ... [A]ll nations are guilty; Germany, too, bears a large part of the blame.