War is also justified on other grounds. Georg Wilhelm Friedrich Hegel thought that war was the catalyst through which the purpose of mankind was brought to fruition. Thus, according to this perception, humanity had to either accept war or stagnate. It was Friedrich Nietzsche who provided the most pervasive justification for war of any type, and the romanticized concept of a just war for a just cause. In Thus Spake Zarathustra, Nietzche said that "a good war hallows every cause." American historians often cite Nietzsche as the philosophical guru for the Nazis in the Germany of the 1930s and 1940s; however, Americans have justified their own wars right down, along with the actions of seemingly countless American surrogat

Dubik, Charles M. "Human Rights, Command Responsibility and Walzer's Just War Theory." Journal of Philosophy and Public Affairs, 2 (1978): 354-371.

In the modern era, revolutions and civil wars are largely guerrilla actions. Guerrilla warfare as a form of resistance to foreign occupation or an unpopular domestic government has been around "for the better part of forever . . . ." Guerrilla warfare is "usually the struggle of a weak people against superior numbers and technology. Guerrilla armies have to be built from scratch, amongst a people whose original military organization proved inadequate or even non-existent." In such a context, people must be persuaded to fight in a guerrilla force, as opposed to being forced into an army by government. Guerrilla leaders, therefore, must be able to demonstrate "clearly that it is in the people's interest to actually fight." More often than not, such persuasion involves convincing people of the real "possibility of thorough-going social and economic changes after the war." This objective of economic and social change, thus, frequently becomes the justification for the revolutionary action.

Miller, S. R. "Just War Theory and the ANC's Armed Struggle." Quest, 4 (December 1990): 81-102.