Fact Sheet: Understanding the New START Agreement

Updated February 2023

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 and it entered into force on February 5, 2011. 
• The Russian Federation extended the treaty on January 27, 2021 and the United States followed suit on February 3, 2021 for a period of five years until Feb. 5, 2026. 
• The United States determined that Russia was in breach of the New START treaty on January 31, 2023. Moscow allegedly refused to allow inspectors on its territory and stonewalled U.S. efforts to discuss the issue. 
• Russian President Vladimir Putin declared that Russia was “suspending” its participation in New START on February 21, 2023.

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

Central Limits Under New START

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 10 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.

Treaty Suspension

Russian President Vladimir Putin declared in late February 2023 that Russia was “suspending” its participation in New START. He framed the step as necessary given (imagined) U.S. provocations, but in reality it merely confirmed what was already Russian policy.

This announcement followed a series of implementation issues. The United States determined that Russia was not in compliance with the treaty in January 2023. A State Department Spokesperson explained, “Russia’s refusal to facilitate inspection activities prevents the United States from exercising important rights under the treaty and threatens the viability of US-Russian nuclear arms control.” In August 2022, the Kremlin blocked treaty-bound inspections visits to its facilities and in November 2022, Moscow postponed the treaty’s bilateral consultative commission. 

As yet, there has been no finding of a material breach of treaty limits, and Russia and the United States remain below the 2018 deployment limits.