" Obama was the fourth president I had worked for who said outright that he wanted to eliminate all nuclear weapons (Carter, Reagan, and Bush 41 were the others). Former secretaries of state Henry Kissinger and George Shultz, former defense secretary Bill Perry, and former senator Sam Nunn had also called for “going to zero.” The only problem, in my view, was that I hadn’t heard the leaders of any other nuclear country—Britain, France, Russia, China, India, or Pakistan—signal the same intent. "