On the evening of , Einstein delivered a speech that would become the cornerstone of his political activism. It was a lecture delivered at the Roosevelt Hotel in New York City for the "Emergency Committee of Atomic Scientists." The title was chillingly direct: "The Menace of Mass Destruction."

But in a broader sense, his work had profound effects:

Gentlemen, I must state this plainly: The splitting of the atom required three years of intense labor in the laboratory. To wipe out every city on the planet, it will require only three seconds of bad judgment.

The speech "The Menace of Mass Destruction" was indeed delivered by Albert Einstein on December 11, 1947, at the Carnegie Institute of Washington, in Washington D.C. While minor variations of the text may exist, the above version represents a faithful and detailed rendering of Einstein's words.

To understand Einstein's work on mass destruction, one must look back to 1939. Fearing that Nazi Germany was developing nuclear weapons, Einstein signed a letter to President Franklin D. Roosevelt urging the United States to begin its own research. This eventually led to the Manhattan Project.