Nominations of Mark T. Esper to be Secretary of the Army ; Robert L. Wilkie to be Under Secretary of Defense for Personnel and Readiness ; Joseph D. Kernan to be Under Secretary of Defense for Intelligence ; and Guy B. Roberts to be Assistant Secretary of Defense for Nuclear, Chemical and Biological Defense Programs : hearing before the Committee on Armed Services, United States Senate, One Hundred Fifteenth Congress, first session, November 2, 2017.