The success of the Manhattan Project meant that the nightmare scenario he feared—a Nazi bomb—was averted, but the reality was a new terror. The devastation wrought upon Japan in August 1945 deeply shook him.
However, the speech was not without impact. It galvanized the Pugwash Conferences (scientists concerned about nuclear war), influenced the Non-Proliferation Treaty (NPT), and inspired generations of anti-nuclear activists.
If you are looking for the most complete and "updated" version of his stance, the Russell-Einstein Manifesto The success of the Manhattan Project meant that
The Blueprint for Global Survival: Re-examining Albert Einstein’s "The Menace of Mass Destruction"
Einstein’s journey towards this warning started, ironically, with a letter. In 1939, concerned that Nazi Germany was developing atomic weapons, Einstein signed a letter to President Franklin D. Roosevelt, urging the U.S. to begin its own research. Roosevelt, urging the U
There is no secret to the atomic bomb, and there is no defense against it. Nations cannot rely on monopoly or on technological superiority for their security. If a new war breaks out, atomic weapons will inevitably be used, and they will bring about the destruction of our civilization.
: Einstein argued that the world had become a single community and that the "fate of tomorrow" for all nations was being decided on the international stage. In a future war
Einstein argued that the concept of absolute national sovereignty was obsolete in the atomic age. In his view, as long as powerful nations operated without a binding international legal framework, war remained a statistical certainty. He viewed the traditional nation-state model as an anarchist system that naturally bred conflict. 2. The Fallacy of "Peace Through Strength"
Here is the crux: National sovereignty and military secrecy are incompatible with human survival. The bomb has rendered traditional military victory obsolete. In a future war, there will be no victors—only the living and the dead.