What were the main ideas for u. s. involment in world war 1

German U-boats sunk many American ships, the Zimmermann note, and the U. S. had strong economic ties with its allies.

The primary reasons that the U. S entered WW1 was for one, a German U Boat sank the Lusitania which had many Americans aboard even though it was a British ship, and because of the Zimmerman Telelgraph, a message sent to Mexico by Germany urging Mexico to declare war on the United States. The British intercepted this telegraph and told the U. S in order to convince them to join the war.