Albert Einstein and Leo Szilard, both prominent physicists, drafted a letter addressed to President Franklin D. Roosevelt, expressing their concerns over the potential for Nazi Germany to develop atomic bombs. The letter detailed the scientific discoveries related to nuclear fission, emphasizing that uranium could be used as a source of significant power, much greater than any conventional explosives at the time. They urged the President to consider funding the development of a nuclear weapon as a means of safeguarding the U.S. and its allies against the expanding threat of fascism during World War II. Einstein, a refugee from Germany, was particularly aware of the dangers posed by the Nazi regime, making their message urgent and significant.The letter was sent to Roosevelt through Alexander Sachs, an investment banker and friend of the President. It marked the beginning of a governmental interest in nuclear research which would eventually lead to the establishment of the Manhattan Project. This project would aim to harness nuclear technology for military purposes, culminating in the development of the first atomic bombs. The initiative would not only change the course of the war but also redefine the future of global diplomacy and warfare in the post-war era, establishing nuclear weapons as pivotal instruments in international relations and military strategy.