Why did the US start the war in Europe?

The United States became involved in the second world war while it was supporting our allies borne of the first world war. We declared war on Japan after that country, while seeking our neutrality in diplomatic channels secretly planned and attacked our ports in Hawaii. Hawaii was a protectorate of ours and not a state at the time. Japan and Germany had signed an agreement (pact) to support each other against what they thought was a meddlesome nonaligned country. We had lost thousands of cargo tonnage on the open sea due to the sinking of our ships by German U-boats (submarines), while only trying to continue supporting Great Britain against the axis powers of Japan and Germany.