Part I is devoted to Niels Bohr's mission to promote an "open world" between nations, that is, full sharing of information in the scientific and technical, as well as in the cultural spheres the scientific and technical, as well as in the cultural spheres. He started his mission immediately upon escaping from Nazi-occupied Denmark in the autumn of 1943, when he realized that the bomb was on the way to becoming a reality. As he wrote in 1944, he considered that the existence of the atomic bomb "would not only seem to necessitate but should also, due to the urgency of mutual confidence,...