Why did Zimmerman choose to send the message through the U.S. state department?

Zimmerman chose to send the message through the U.S. State Department as a means of discreet communication, leveraging diplomatic channels to avoid interception by British intelligence. By utilizing the official diplomatic route, he aimed to ensure that the message reached its intended recipient—Germany's ambassador to Mexico—without raising immediate suspicion. This method also reflected the urgency and importance of the message, which sought to propose a military alliance with Mexico against the United States during World War I.