Would the United States still enter the European war?

If Hitler had not declared war on the United States, could Britain still win and would America nevertheless enter the German war?

Britain could still win, and American involvement would remain likely because the United States would already be fighting Japan and supporting Britain, though the route would differ.

Britain could still have defeated Germany, although the route and timetable would differ without American troops in Europe. The United States would probably continue supplying Britain even if it did not immediately enter the German war. Complete separation would be difficult once America was fighting Japan alongside a country already at war with Germany. Military cooperation, shared enemies, and Atlantic support would keep drawing the conflicts together. American entry is not automatic in this scenario, though neutrality toward Germany would become hard to sustain.