Niels Bohr’s Political Crusade during World War II

Abstract

Niels Bohr's "Open Letter to the United Nations", published in 1950 and pleading for an "open world" between nations, is well known. It is also well known that Bohr took part in the Manhattan Project during World War II. This article describes in some detail how Bohr's idea of an open world not only matured during his war-time exile, but even constituted the basis for a veritable crusade on Bohr's part in the course of the war to convince statesmen of the necessity to think differently in the post nuclear-bomb era. (edited)