FDR's decision to draft the first group of young men in the summer of 1940 was therefore risky because the country wasn't at war and the draft would be on the mind of voters in an election year (the election was ten days earlier and FDR won his third term handily).
The newspapers and cinema newsreels were now full of the news of Hitler's cynical pact with Stalin whereby in 1939 they divided up Poland. The the German army earlier in 1940 overran Norway and Denmark on April 9, then Holland, Belgium and Luxembourg on May 10, and France on May 12. Fear of Hitler, which for many dated back a year to Kristallnacht in 1938, following the annexation of Austria and the invasion of Czechoslovakia. Hitler sensed the fear and was emboldened by the lack of resistance among the European powers.
Meanwhile Stalin overran the three Baltic states and annexed them. Neville Chamberlain was ousted and Winston Churchill took over the Prime Ministerist of Britain, stepping up preparation for war. The United States had a poorly trained standing army of only about 200,000 soldiers. FDR took the step of requiring 16 million young men to register with the Selective Service. At the first lottery in Washington, D.C., Secretary of War Henry Stimson was blindfolded and ceremonially scooped out numbers.
By the end of World War II, 19 million men were drafted and 10 million were inducted. The draft lapsed for a while between the World War II and the Cold War, but Truman then restarted. It was not ended until 1973, when Nixon introduced the all-volunteer program.
Most Americans rejoiced about the end of the draft, but in 1999 the historian Stephen Ambrose explained the downside:
Today, Cajuns from the Gulf Coast have never met a black person from Chicago. Kids from the ghetto don't know a middle-class white. Mexican-Americans have no contact with Jews. Muslim Americans have few Christian acquaintances ... But during World War II and the Cold War, American [men] from every group got together in the service, having a common goal — to defend their country.