Russia is in the middle of a broad modernization of its strategic and nonstrategic nuclear forces, including both new programs and some that have been underway for many years. As of early 2017, the authors estimate that Russia has a military stockpile of roughly 4,300 nuclear warheads assigned for use by long-range strategic launchers and shorter-range tactical nuclear forces. Of these, roughly 1,950 strategic warheads are deployed on ballistic missiles and at heavy bomber bases, while another 500 strategic warheads are in storage along with some 1,850 nonstrategic warheads. In addition to the military stockpile for operational forces, a large number of retired but still largely intact warheads await dismantlement, for a total inventory of around 7,000 warheads. The modernizations, combined with an increase in the number and size of military exercises and occasional explicit nuclear threats against other countries, contribute to growing concern abroad about Russian intentions. These concerns, in turn, drive increased defense spending, nuclear modernization programs, and political opposition to reductions in Western Europe and the United States. Read this free-access article in our subscription journal.