How did the United States end up at war with Germany in 1941? A. The United States declared war on Germany after the London blitz. B. After America came to Britain's aid with the "lend-lease" program, Germany declared war on the U. S. C. After the U. S. declared war on Japan, Germany declared war on the U. S. D. The U. S. declared war on Germany and Italy at the same time it declared war on Japan.