One of President Donald Trump's first actions after entering office was to direct Secretary of Defense James Mattis to "initiate a new Nuclear Posture Review to ensure that the United States nuclear deterrent is modern, robust, flexible, resilient, ready, and appropriately tailored to deter 21st-century threats and reassure our allies."1 Secretary Mattis has since reportedly directed that the new Nuclear Posture Review (NPR) be completed in six months.2 This new 2017 NPR will be the fourth in a series, following the 1994, 2001, and 2010 NPRs. There has been both significant consistency in these previous NPRs and some significant innovations.3 The forthcoming NPR will confront two overarching questions: First: what are the changes in the security environment since the 2010 NPR? And, second, what do these changes suggest regarding US policies and requirements? The discussion here focuses only on Russia, but there are important parallels with regard to US-Chinese relations and our allies in Asia that are worthy of serious consideration.