What 3 factors pulled the US into World War 1?

The 3 largest factors that brought the US into WWI were Alliance, Nationalism, and Imperialism. Alliances of the European nations created the system pitting nation versus nation. The Nationalism aspect is part of subjugated nationalities created in the alliances of the European Nations. The Imperialistic competition to develop vast and strong empires created conflict which could not be settled with peace.