Updated May 2021
Background
- The United States and Russia signed the New Strategic Arms Reduction Treaty (New START) on April 8, 2010.
- The United States ratified the treaty on December 22, 2011. The treaty was extended by the Russian Federation on January 27, 2021 and by the United States on February 3, 2021.
- Previous Treaties: Strategic Arms Reduction Treaty (START, 1991), Strategic Offensive Reductions Treaty (SORT, or Moscow Treaty, 2002).
- New START intended as a placeholder treaty that would set the groundwork for future negotiations.
Importance to U.S. National Security
The provisions of New START limit the nuclear arsenals of both signatories, but they also increase and strengthen verification measures and transparency. By encouraging increased communication between the two countries, the treaty reduces the risk of miscalculation.
What the Treaty Does
Table I. Central Limits Under New START
| Deployed Warheads | 1,550 warheads* |
| Deployed Delivery System | 700 ICBM and SLBM launchers and heavy bombers |
| Deployed and Non-deployed Delivery Systems | 800 ICBM and SLBM launchers and heavy bombers |
Number of Warheads
New START required both countries to limit the number of deployed warheads to no more than 1,550 by February 5, 2018, which both countries successfully completed. The treaty establishes that the number of warheads on deployed intercontinental ballistic missiles (ICBMs) and submarine launched ballistic missiles (SLBMs) is counted as the number of re-entry vehicles (RVs) on each missile. Heavy bombers are counted as one warhead against the total regardless of how many warheads they carry.*
Number of Launchers
New START limits both parties to a maximum of 800 deployed and non-deployed ICBM and SLBM launchers. Of those 800, no more than 700 delivery systems may be deployed at any time. Neither party may convert ICBM or SLBM launchers into launchers for missile defense systems.
Dates of Effect
New START entered into force on February 5, 2011. Both parties were required to reach the limits on warheads and launchers specified in the treaty by February 2018, and have stayed at or below those levels ever since. The duration of the treaty is ten years from entry into force (February 2021), but both parties agreed to extend the treaty for a subsequent five years on February 3, 2021. Each party is entitled to withdraw from New START if it is decided that “extraordinary events related to the subject matter of this treaty have jeopardized its supreme interests.” The treaty would terminate three months after a notice of withdrawal was issued.
Verification Measures
Data Exchanges
Within 45 days of New START’s entry into force, Russia and the United States were required to report the numbers of deployed warheads, and deployed and non-deployed missiles and delivery systems of strategic weapons. This information was compiled into a database, which is updated with changes every six months. Inspections are intended to verify the data that is exchanged between the two countries.
Types of Inspections
New START allows for 18 on-site inspections per year. Inspections may include confirming the number of reentry vehicles on deployed ICBMs and SLBMs, confirming numbers related to non-deployed launcher limits, and counting the number of weapons onboard or attached to heavy weapons bombers. The United States and Russia are allowed ten Type 1 inspections, conducted on short notice at bases that deploy strategic launchers. Each side can choose one ICBM or SLBM to inspect and count the warheads. This type of inspection is designed to deter both sides from deploying a missile with more than the declared number of warheads. Eight Type 2 inspections are allowed each year, conducted at facilities that are designated only for non-deployed delivery systems.
Weapons Not Regulated by New START
New START does not restrict the number of non-deployed ICBMs and SLBMs but it does keep track of them to verify that they are not deployed. New START only regulates strategic nuclear weapons; tactical nuclear weapons are not included in the treaty.
