Nevertheless, the idea that wars are fought over world-historical stakes has by no means died. We remain prey to the belief that victory proves something about the course of history. World War II in particular seemed, to some of the victorious Allies, to prove that Western liberalism was destined to triumph, while to others it seemed just as clearly to prove the same thing about communism….Of course, any such belief is nonsense….Yet the horror and violence of war overwhelm our modern senses so much that we continue to look for great ultimate millennial meaning in the fact of victory or defeat.
The inevitable consequence is that we find it difficult to bring our wars to any genuinely accepted conclusion. If the world-historical meaning of Allied victory in World War I or World War II is that history intends Western democracy to triumph everywhere, then of course the wars cannot end until Western democracy triumphs everywhere….There is no law of victory to specify any lesser prize. There is no room to negotiate an end to the war because the expectations of the victor have become too absolute to permit a compromise.
Modern victors believe they are riding the wave of history, and it follows that they claim limitless rights. (p.259)
As I mentioned last week , one of Whitman’s arguments in the book is that the understanding of war changed from thinking of its outcome in terms of chance and Fortune to thinking of it in terms of Destiny. As a result, the outcome of a war is invested with much greater significance as the “verdict of history.” When winning a conflict implies that some sort of final judgment has been rendered by History on the beliefs and values of both belligerents, that tends to make people on both sides of the conflict treat atrocious behavior as legitimate because it is deemed necessary for victory. It encourages governments to start and continue wars that are rooted in intangible, ideological goals that require the destruction and replacement of entire regimes.
The danger of using rhetoric about “right” and “wrong” sides of history isn’t just that it’s self-justifying nonsense, but that it is used to authorize unjust behavior against others and it makes it more difficult to resolve and avoid conflicts. If you believe that yours is the side favored by History, you have fewer incentives to compromise and reach negotiated solutions with your rivals and adversaries, and if both sides believe that their ideology or cause is destined to prevail it becomes extremely difficult to avoid war and equally difficult to limit it when it happens. Needless to say, it would be very unusual to believe that there is a “right side” of History if one’s country and/or political values weren’t currently dominant or in the ascendant.
Camus said  that “the future authorizes every kind of humbug.” So does “History,” which is why there will always be those wanting to identify their cause with the “right side” of it.