b'HKS Professor Matthew Bunn, co-principal investigator for the Belfer Center\\u2019s Project on Managing the Atom, explains how the US nuclear arsenal is managed, what the outgoing Obama administration\\u2019s $1 trillion commitment to modernization will entail, and what, if any, changes can be expected under President Trump. He also discusses the state of non-proliferation and the greatest nuclear threats the world faces today.'