Ash Carter started his career as a researcher in theoretical physics but quickly became enamored with public policy. As a Massachusetts Institute of Technology scientist, he rose to prominence in 1984 with a report ripping President Reagan’s Star Wars missile-defense initiative as a dud. Recruited by the Clinton administration as a Pentagon assistant secretary in 1993, he helped oversee the removal of nuclear weapons from Ukraine, Kazakhstan and Belarus after the end of the Cold War. During the Obama administration, Carter was undersecretary of Defense from 2011 to 2013 and then Pentagon chief from February 2015 until the end of the administration. During that time, he had to wrestle with the challenge from China and carry out that administration’s much publicized – and much criticized – “pivot” to Asia. The blunt-speaking Carter also looked for ways to encourage start-ups in Silicon Valley and other tech centers to do military work and help the U.S. meet the Chinese challe