WORLD HISTORY

Detailed explanation-1: -The note revealed a plan to renew unrestricted submarine warfare and to form an alliance with Mexico and Japan if the United States declared war on Germany. The message was intercepted by the British and passed on to the United States; its publication caused outrage and contributed to the U.S. entry into World War I.

Detailed explanation-2: -This telegram, written by German Foreign Secretary Arthur Zimmermann, is a coded message sent to Mexico, proposing a military alliance against the United States.

Detailed explanation-3: -The telegram was considered perhaps Britain’s greatest intelligence coup of World War I and, coupled with American outrage over Germany’s resumption of unrestricted submarine warfare, was the tipping point persuading the U.S. to join the war.