I do believe it was to quickly ruin their industries, dropping the nukes on Hiroshima and Nagasaki destroyed their largest cities and their storages, costing them a bunch of lives and money in order to repair the damages. And to make them surrender, after the first dropping, Germany still wasn't going to quit because they still had ammo and troops, so US bombed Germany's last supplies.
Germany was bombed by the US Air Force during the day, and by the British Air Force over the night, carrying out a campaign to destroy cities, communications, transport and military forces. The destruction of factories wanted to disable or limit the production of weapons, capacity of weapons, which was necessary for the German military forces to continue the fight. Also, destroying roads, bridges, airports, railways and ports wanted to prevent the delivery of weapons to German military forces. Destruction of cities directly influenced the morale of the local population, although there were cases of the opposite effect. The bombing was also aimed at destroying special targets, such as synthetic fuels, secret weapons and secret places, the launch of missile bombs V1 and V2. It seems that the bombing has positively fulfilled its targets, as the offensive capabilities of the German army have dramatically decreased.
After World War l the United States stuck with a strict policy of isolationism. The American people didn’t want to be involved in European affairs. Accepting the refugees would’ve been a way for the U.S. to get dragged into the war. We see in the later years after the Imperial Japanese attacked Pearl Harbor where isolationism in the States becomes a distant memory and where the U.S. begins taking position on the world stage.
