The Atlantic Ocean was home to submarines, naval ships, and also the transfer of goods. Domination on the seas was necessary for getting supplies, people, and weapons from place to place. With new technology, ideas were able to spread quickly and new warfare was created by both sides such as poison gas. Communication also played a role in getting the United States to join the war. The interception of the Zimmermann Telegraph as well as the sinking of the RMS Lusitania both helped persuade the US in joining the war.