This op-ed originally appeared in CNN.
Kingston Reif is the Director for Disarmament and Threat Reduction Policy at the Arms Control Association. You can follow him on Twitter at @KingstonAReif. The opinions expressed in this commentary are his.
(CNN)The possibility of Donald Trump winning the presidential election this November has renewed media and public interest in one of the most important responsibilities of the president: commanding America's massive nuclear arsenal and averting nuclear war.