âTomorrow, the Worldâ Review: From Isolation to American Empire Where did Americaâs global dominance begin? In Stephen Wertheimâs view, look to the fall of France in 1940. Crowd in New York City celebrating V-E Day, May 8, 1945. Photo: Universal Images Group/Getty Images By Paul Kennedy Jan. 8, 2021 11:53 am ET How fast it was, really, for America to become No. 1. It took a mere five summersâso short a time in the grand sweep of Great Power politicsâfor a vague ambition held in the minds of a small group of American intellectuals before 1940 to become the firm grand strategy of the Republic by June 1945. One month earlier than that, in May, the Supreme Allied Commander of the Westâs forces in Europe, five-star American Army Gen. Dwight Eisenhower, had accepted the Nazi surrender. Six thousand miles away, and only a few weeks later, the nations of the free world met to sign the U.N. Charter in San Francisco and formed a new international order very much along American lines. Even as that historic event was happening, the President of the United States was preparing, confidently, to further arrange the worldâs future at Potsdam. And while Harry Truman was sailing back from Europe after the Potsdam Conference, he ordered the dropping of the first atomic bomb upon a distant, battered Japan. This was world power as had never been seen before; little wonder that both its supporters and its few remaining doubters shook their heads in awe. Was this not, indeed, manifest destiny?