America was supplying allied powers with war materials and supplies aiding their effort in the war. The Zimmerman Telegram also is known as unrestricted submarine warfare was a policy that the Germans carried out to delay the transportation of supplies from the United States to their allied powers, who were at war with Germany.
The telegram written by Arthur Zimmerman, a German, was intercepted by the British who decoded the message who was for a German Ambassador in Mexico. It stated if the United States were to join the war supporting the allies the German Ambassador would consult Mexico’s president to make a secret alliance. The Germans would fund Mexico to attack the United States which would allow Mexico to take back Texas, Arizona, and New Mexico. And the Germans wanted to use Mexico to convince the Japanese to support their cause. When the U.S heard this from the British that furthered their cause to join the war and abandon their policy of neutrality.
HistoryGuy. Control of the Atlantic Ocean was essential to Great Britain's success in World War II because D. Britain was an island nation dependent "on shipping for the supplies it needed." Without access to Atlantic shipping lanes, Britain would have starved and been without war supplies from the Americans. (hope this helps )