Albert Einstein's views on the atomic bomb were marked by a complex interplay of advocacy for scientific progress and deep ethical concerns about nuclear weapons. Initially, he urged the U.S. to develop atomic capabilities in response to potential threats from Germany, notably through a 1939 letter to President Roosevelt. However, as the consequences of atomic warfare became evident, Einstein expressed regret for his role in initiating the Manhattan Project, famously stating he made a significant mistake by endorsing the bomb's development. Following the bombings of Hiroshima and Nagasaki, he became a strong proponent of nuclear disarmament and advocated for the peaceful application of atomic energy. Einstein emphasized the moral responsibilities of scientists and the need for international cooperation to prevent future nuclear conflicts, warning that future wars could devastate civilization. His reflections highlight a commitment to ethical considerations in scientific advancements and a profound concern for humanity's future.