Top former U.S. administration officials last week expressed support for a five-year extension of the 2010 New Strategic Arms Reduction Treaty ( New START ), the last remaining arms control agreement between the United States and Russia that is set to expire in February 2021. “Put me down in the column of extension, and the reason for that is the clock is running,” said Admiral (ret.) Michael Mullen, former Chairman of the Joint Chiefs of Staff, during an April 29 event hosted by the Arms Control Association. Rose Gottemoeller, lead U.S. negotiator for the treaty, and Lt. Gen. (ret.) Frank...