NOTE: SPEAKER CHANGED HIS TOPIC. RATHER THAN PRESENTING THE TALK OUTLINED BELOW, HE SPOKE ABOUT RECENT DEVELOPMENTS RELATED TO DISARMAMENT -- POLITICAL, DIPLOMATIC AND TECHNOLOGICAL. Throughout history there has been a close relation between physics and the military. Since WWII physicists have played a particularly important role in U.S. national security. I will discuss two recent and current contributions: The application of physics to photo reconnaissance from space, and nuclear non-proliferation and the moratorium on underground explosive testing of nuclear weapons. I will also discuss new challenges emerging at the beginning of the 21st century, and ethical concerns that have been raised about the involvement in scientists in weapons development.