To what extent did Germany threaten American people, territory, and interest?

Germany threatened the American people, territory and interest by going to war with them towards the end of World War II. America managed to stay out of the war until the Japanese bombed Pearl Harbour. When America declared war on the Japanese, Germany joined the Japanese side. Hitler's justification for this was that President Roosevelt's hostilities towards Germany. Hilter declared that Roosevelt was becoming increasingly hostile towards Germany and therefore Germany was joining the war with Japan against the USA