The Secretary of Defense is the top official in the U.S. Department of Defense. Primary roles include: Advising the president on military matters, formulating American defense policy, and for following through with approved military policies. Together, the Secretary of Defense and the President form the two-person National Command Authority, which can launch nuclear weapons with consensus between them. The Secretary of Defense is also the supervisor of the Joint Chiefs of Staff, the group comprised of the heads of all branches of the U.S. Armed Forces.

Department of Defense Headquarters (the Pentagon) - Arlington, VA