The action of Admiral Hall is unethical. When the Room 40 deciphered Zimmerman telegram, Admiral Hall got to know how important this information was and the greatness of deciphering enemy’s ciphertext. He got to know that Germany will begin his plan in two weeks, but he chose not to tell America immediately. However, when the allies wanted America to join the war, Admiral Hall had to tell America this information. Hall did not want to provide Zimmerman telegram to America, but he finally did, so why didn’t tell America earlier? Hall could evaluate the cause and effect or ask for the intention of America earlier. Admiral Hall made a decision that made no sense since his wish of not letting Germany know they has deciphered the text is disclosed finally. He used the hand of Mexicans to try to hide this information, but he could choose to do this as soon as he got the decipher text. Hall made a decision that may cause more problems. The Zimmerman telegram provided the information that the Germany will initiate the attack in two weeks, but to be prepared for the attack, America needs more time. Two weeks are short but still valuable, but Hall’s decision shorten this time and may cause more casualties. Thus, the decision of Admiral Hall is unethical.