The United States and Russia largely continue to reduce their arsenals of long-range nuclear weapons in line with the mandates of the New Strategic Arms Reduction Treaty (New START), with the exception of an increase in Russia’s deployed strategic warheads, according to the latest aggregate data released over the weekend on treaty activity.

The bilateral accord, under which both countries remain in good standing despite the Kremlin’s withdrawals this week from other nuclear security and nonproliferation agreements, requires the U.S. and Russia to by February 2018 cap their nuclear arsenals at 700 deployed ICBMs, submarine-launched ballistic missiles, and heavy bombers; 1,550 fielded strategic warheads; and 800 deployed and nondeployed long-range launchers.

A nuclear detonation. Photo: U.S. Energy Department
A nuclear detonation. Photo: U.S. Energy Department

The Oct. 1 numbers, containing data declared as of Sept. 1, say that since the last numbers released on July 1, the United States has reduced its deployed ICBMs, SLBMs, and heavy bombers from 741 to 681; Russia remains below the treaty limit, going from 521 to 508. During that time the U.S. also reduced its deployed strategic warheads from 1,481 to 1,367; Russia increased its own from 1,735 to 1,796. Both countries reduced their counts of deployed and non-deployed long-range delivery systems, with the U.S. cutting back from 878 to 848 and Russia from 856 to 847.

Critics of New START say the initial asymmetries in the two countries’ nuclear arsenals have led the U.S. to make deeper cuts than has Russia, noting that Moscow has increased the number of deployed warheads since the treaty’s entry into force in 2011.

Russia’s missile launchers, in particular, were already below the treaty limit upon entry into force, meaning that, in contrast to the U.S., it would not need to make any reductions. Additionally, tactical nuclear weapons are not covered by the treaty, leaving a disparity between the couple hundreds of deployed U.S. tactical nuclear weapons and the thousands that Russia has fielded.

House Armed Services Committee Chairman Mac Thornberry (R-Texas) said in a statement Tuesday, “The Obama Administration hailed the New START Treaty as the ‘cornerstone’ of its efforts to ‘reset’ our relations with Russia. This latest development is further evidence of what this ‘reset’ actually is— a mistake and a failure. The numbers are clear: while we cut our U.S. nuclear forces, the Russians have built more.”

However, Hans Kristensen, director of the Nuclear Information Project for the Federation of American Scientists, noted in his analysis of the new numbers that Russia’s increase in deployed strategic warheads is “a temporary fluctuation caused by introduction of new types of launchers that will be followed by retirement of older launchers before 2018.”

Kristensen said that while the U.S. has decreased its stocks of deployed strategic warheads by 433 since 2011, and Russia has increased its own by 259, the disparity has “no negative implications for strategic stability.”