How did isolationism act as a deterrent to US participation in the war?

U. S. isolationism between the world wars was a bipartisan policy, drawing support from across the social and political spectrum. Its fundamental postulate was not absolute withdrawal behind the Atlantic and Pacific Oceans, but a belief that the United States should retain the independence in foreign policy that had been its norm until 1917. America’s direct losses in World War I were less significant in reinforcing that position than a growing sense that the war had been fought over nothing; that America’s former allies were less concerned with peace and justice than with victory and plunder; and that the United States had obtained nothing from its participation except uncollected debts. In January 1937 almost three-fourths of the responses to an opinion poll believed that American participation in World War I had been a mistake.