U.S. Department of State

Key Point: Neither the United States nor Russia currently deploys rail-mobile ICBM launchers. If a Party develops and deploys rail-mobile ICBMs, such missiles, their warheads, and their launchers would be subject to the Treaty.

Definitions: The New START Treaty defines an ICBM launcher as a “device intended or used to contain, prepare for launch, and launch an ICBM.” This is a broad definition intended to cover all ICBM launchers, including rail-mobile launchers if they were to be deployed again in the future. There is no specific mention of rail-mobile launchers of ICBMs in the New START Treaty because neither Party currently deploys ICBMs in that mode. Russia eliminated its rail-mobile SS-24 ICBM system under the START Treaty. Nevertheless, the New START Treaty’s terms and definitions cover all ICBMs and ICBM launchers, including a rail-mobile system should either Party decide to develop and deploy such a system.

• A rail-mobile launcher of ICBMs would meet the Treaty’s definition for an ICBM launcher. Such a rail-mobile launcher would therefore be accountable under the Treaty’s limits.
• Because neither Party has rail-mobile ICBM launchers, the previous definition of a rail-mobile launcher of ICBMs in the START Treaty (“an erector-launcher mechanism for launching ICBMs and the railcar or flatcar on which it is mounted”) was not carried forward into the New START Treaty.
• If Russia chose to develop and deploy rail-mobile ICBMs, such missiles and their launchers would be subject to the Treaty and its limitations. Specific details about the application of verification provisions would be worked out in the Bilateral Consultative Commission. Necessary adjustments to the definition of “mobile launchers of ICBMs” – to address the use of the term “self-propelled chassis on which it is mounted” in that definition – would also be worked out in the BCC.

Accountability: A rail-mobile launcher containing an ICBM would meet the definition of a “deployed launcher of ICBMs,” which is “an ICBM launcher that contains an ICBM.”

• Deployed and non-deployed (i.e., both those containing and not containing an ICBM) rail-mobile launchers of ICBMs would fall within the limit of 800 for deployed and non-deployed launchers of ICBMs and SLBMs and deployed and non-deployed heavy bombers.
• The ICBMs contained in rail-mobile launchers would count as deployed and therefore would fall within the 700 ceiling for deployed ICBMs, SLBMs, and heavy bombers.
• Warheads on deployed ICBMs contained in rail-mobile launchers therefore would fall within the limit of 1,550 accountable deployed warheads.

Applicable Provisions: Separate from the status of the rail-mobile ICBM launcher, all ICBMs associated with the rail-mobile system would be Treaty-accountable, whether they were existing or new types of ICBMs, and therefore would, as appropriate, be subject to initial technical characteristics exhibitions, data exchanges, notifications, Type One and Type Two inspections, and the application of unique identifiers on such ICBMs and, if applicable, on their launch canisters.