Final answer:
People who opposed World War I saw all wars as fundamentally evil, often stemming from pacifist ideologies or skepticism about the motives behind the war. Influential individuals, socialists, working-class citizens, and those who adhered to America's historical non-interventionism played a role in this opposition. The post-war period saw heightened disillusionment, given the unresolved tensions and the rise of extremist ideologies.
Step-by-step explanation:
These people who opposed World War I believed all wars were evil due to pacifist principles or other ideological reasons. Prominent figures like Andrew Carnegie, Henry Ford, and Jane Addams, as well as sections of society including socialists, pacifists, and segments of the working class, vocalized their opposition. Their resistance was influenced by a variety of factors, such as the belief that the war was a "rich man's war but a poor man's fight," a sentiment captured by figures like Samuel Gompers. The strong dissent among Americans was, in part, a legacy of the nation's commitment to non-interventionist foreign policy, which harkened back to the days of George Washington. Moreover, after the war, there was considerable disillusionment regarding the outcomes of World War I, seeing as it did not resolve the initial international tensions and led to the rise of dangerous ideologies like fascism and Nazism.