The period since 1945 has been marked by the absence of war between the world's major powers. Since 1945, we have lived in what John Lewis Gaddis dubbed the "Long Peace." Through the Long Peace we have also had decades of rising incomes, living standards and health throughout the world, especially in the United States. The dominant foreign policy ideas in America at the time were represented by a movement called "America First." It took Hitler and World War II to make Americans recognize that, for a country of America's size and scale, isolation and narrow self-interest would lead to global insecurity and disaster.

Source: CNN January 28, 2017 01:14 UTC