Vann H. Van Diepen is an independent consultant after thirty-four years of U.S. government service on weapons of mass destruction issues. From 2009 to 2016, he was principal deputy assistant secretary of state for international security and nonproliferation (including over two years as acting assistant secretary). From 2006 to 2009, he was national intelligence officer for weapons of mass destruction and proliferation in the Office of the Director of National Intelligence.