After the Zimmermann telegram was deciphered, Admiral Hall chose to withhold the important information regarding the unrestricted submarine warfare and put many Americans’ lives on the line.
The decision itself at that moment seemed unethical because it resulted in the death of many innocent Americans. However, thinking in a larger scale, Hall’s action was justifiable. Firstly, given this war context, the ethical considerations probably weren’t be the top priority for people who dedicated themselves for the future of their country. Instead of thinking about whether their decisions might be ethical, they would probably spending more time weighing up the consequences of their actions, which, in Hall’s case, was the potential long-term consequences of disclosing their advanced cryptographic progression to the world. Hall realized that it might eventually make the British lose the advantage of using their advanced cryptographic techniques to gather the information that would be extremely valuable to them in the war.
Another text written by Sun-Tze in the Art of War says that “if you know your enemies and know yourself, you will not be imperiled in a hundred battles.” Sun-Tze’s words implies that in order to win the battle, not only should us try to gather as much information as we can about the enemies, but also try to avoid exposing any of our own progression to the enemies. That was exactly what Hall did. His action enabled the British to see through German’s plot while keeping the Germany in the dark, hence gaining significant advantages in the long run. In this sense, I believe that Hall’s decision shouldn’t be considered unethical, but simply strategical.