What were the imperialist and the anti-imperialist viewpoints from the late nineteenth and early twentieth centuries?

Imperialists in the late nineteenth and early twentieth centuries believed in the expansion of their nations' power through colonization and the acquisition of territories, arguing that it was a moral duty to civilize "less developed" nations and that it would benefit the economy through new markets and resources. In contrast, anti-imperialists opposed these practices, advocating for self-determination and arguing that Imperialism was morally wrong and often led to exploitation and oppression of colonized peoples. They viewed imperialism as a violation of democratic principles and emphasized the dangers of entangling alliances and military overreach. This debate shaped international relations and domestic policies during that era.