I came to the conclusion that war was an unacceptable way of solving whatever problems there were in the world--that there would be problems of tyranny, of injustice, of nations crossing frontiers and that injustice and tyranny should not be tolerated and should be fought and resisted, but the one thing that must not be used to solve that problem is war. Because war is inevitably the indiscriminate killing of large numbers of people. And that fact overwhelms whatever moral cause is somewhere buried in the history of that war.
Howard Zinn (2012). “Howard Zinn Speaks: Collected Speeches 1963-2009”, p.108, Haymarket Books