The letter was taking very seriously, and stated that Germans would find the power of uranium first if actions were not taken, and must have made Roosevelt think it would put U.S back as the number one power house, and would put them out of every other country’s league as far as war technology goes. Einstein later regretted sending that letter because he feels as if he didn’t send the letter, the bomb wouldn’t have ever been created, or at least would have stalled the finding of it. While we know, if we didn’t make it, the Germans could have made it first and used it to their advantage during WW2. Little Boy and Fat Man were just the beginning. How would Einstein feel if he saw what we have