Question

Why is the Zimmerman telegram considered a major cause of the United States entering World War I? It guaranteed the use of German U-boats against the United Sates Navy. It was proof that Russia had been planning an attack on the United States for years. It showed that there was an attempt by Germany for Mexico to help attack the United States. It proved that the German Foreign Minister, Arthur Zimmerman, was a spy.

Answer 1

It showed that there was an attempt by Germany for Mexico to help attack the US