U.S.-Russian Nuclear Arms Control: Overview and Potential Considerations for Congress

U.S.-Russian Nuclear Arms Control: Overview and Potential Considerations for Congress

U.S.-Russian Nuclear Arms Control: Overview and Potential Considerations for Congress

Updated May 1, 2025 (IF12964)

The United States has periodically sought to advance its national security interests through the negotiation and conclusion of nuclear arms control agreements with its adversaries. In January 2025 remarks, President Donald Trump advocated potential discussions with Russia and China concerning nuclear weapons reductions. Following these remarks, Russian President Vladimir Putin signaled some potential openness to discussing arms control.

Congress plays an important role in arms control, which is implemented pursuant to treaties or agreements negotiated by the executive branch. The Senate considers providing advice and consent to the ratification of treaties and the confirmation of executive branch nominees for positions in the Department of State (DOS), Department of Defense (DOD), Department of Energy, and the intelligence community. Congress also authorizes and appropriates funds for, as well as provides oversight of, those U.S. government agencies that negotiate, implement, monitor, and verify compliance with treaties and agreements.

Background

During the Cold War and in its aftermath, the United States and the Soviet Union (which Russia and other Soviet republics dissolved in 1991) sought to minimize the costs and risks of nuclear competition and improve so-called strategic stability. Following the 1962 Cuban Missile Crisis, the United States and the Soviet Union created a "hotline" to communicate in a nuclear crisis, which, along with some later risk reduction agreements sought to reduce dangers of an accidental or inadvertent nuclear war.

After the Soviet Union achieved rough parity in strategic nuclear forces with the United States, and began to deploy ballistic missile defenses, the two countries engaged in Strategic Arms Limitations Talks (SALT). The 1972 SALT I Treaty and Anti-Ballistic Missile (ABM) Treaty negotiated by the Johnson and Nixon Administrations and the 1979 SALT II Treaty negotiated by the Nixon, Ford, and Carter Administrations resulted in some limits on strategic nuclear forces and ballistic missile defenses. Subsequently, the Reagan Administration concluded the 1987 Intermediate-Range Nuclear Forces (INF) Treaty, which verifiably destroyed all ground-launched ballistic and cruise missiles of intermediate ranges. The Reagan and George H.W. Bush Administrations negotiated the 1991 Strategic Arms Reduction Treaty (START I), which resulted in the "largest arms control reductions in history," according to DOD. In 2002, the George W. Bush Administration concluded the Moscow Treaty reducing U.S. and Russian strategic nuclear forces to between 1,700 and 2,200 deployed warheads.

The executive branch has also at times withdrawn from arms control agreements, including in 2002 from the ABM Treaty and in 2019 from the INF Treaty, when it deemed these accords to no longer be in the U.S. national security interest.

New START

The United States and Russia are currently parties to the 2010 New START treaty, under which the two countries verifiably reduced their strategic nuclear forces to 1,550 deployed warheads on 700 deployed strategic delivery vehicles (intercontinental ballistic missiles (ICBMs); submarine-launched ballistic missiles; and strategic bombers). In 2021, the United States and Russia exercised a New START provision to extend the Treaty until February 2026. However, since Russia's 2022 invasion of Ukraine, Moscow has declined to conduct or host New START-mandated on-site inspections or participate in consultations.

In February 2023, President Putin announced that Russia would "suspend participation" in New START, citing concerns about UK and French nuclear weapons and also Western efforts to achieve Russia's "strategic defeat" in the war in Ukraine. Russian officials have stated that Russia would observe Treaty limits, but would suspend data exchanges under the Treaty. The DOS has called Russia's suspension "legally invalid" and announced countermeasures. The DOS has also since expressed concerns about Russia's compliance with New START in congressionally-mandated public annual reports.

New START Follow-on Negotiations

In 2020, during the first Trump Administration, U.S. and Russian officials held several meetings to discuss arms control issues, including potential limits on Russian nonstrategic nuclear weapons, which are nuclear weapons deployed on delivery vehicles with ranges shorter than strategic nuclear weapons. The United States also sought to include China, which declined to participate, in talks.

In 2021, Biden Administration officials engaged with their Russian counterparts in a Strategic Stability Dialogue to "lay the groundwork for future arms control and risk reduction measures." The United States advocated including all Russian nuclear weapons in a notional agreement. Russia, in turn, proposed discussing nuclear and non-nuclear weapons, missile defense, outer space, and other issues, which, Russia argued, were impacting strategic stability. No bilateral nuclear arms control dialogue has taken place since 2022 despite Biden Administration statements that the United States was willing to return to such talks "without preconditions."

Potential Considerations for Congress

Members of Congress have deliberated about the extent to which current and future U.S.-Russian nuclear arms control is in the U.S. national security interest. Some Members have argued that there is "continued value" in such arms control, and "urged" talks for a new treaty and mutual observance of New START limits. Other Members have expressed concerns about Russia's noncompliance with arms control commitments, urged DOD to prepare for a future where Russian nuclear weapons are not bound by New START, and stressed the importance of U.S. nuclear modernization.

Arms control and U.S. nuclear modernization

Congress may consider how arms control, and the timelines for any potential limits on U.S. capabilities, interact with the progress of U.S. nuclear modernization. The United States is modernizing its nuclear forces, which currently includes the procurement of a new ICBM; a new strategic bomber; a new ballistic missile submarine; updates to its nuclear command, control, and communications (NC3) system and regional deterrence capabilities; and the modernization of its nuclear weapons complex.

The Congressional Budget Office (CBO) estimated in 2025 that the operation and modernization of U.S. nuclear forces could total over $95 billion a year. DOD has continued to prioritize nuclear modernization, but President Trump has also stated that "tremendous amounts of money are being spent" on nuclear weapons and expressed hope that the United States, Russia, and China could decrease defense spending.

Russia's nuclear capabilities of concern

Congress may consider whether Russian nuclear weapons present a threat to the United States that could be managed through arms control. Whether President Putin may seek to build up Russian strategic nuclear forces after New START expires in February 2026 is uncertain. Some Russian officials have suggested that new U.S. ballistic missile defense developments may impact Russia's willingness to maintain Treaty limits. According to open sources, Russia, like the United States, has reserve nuclear warheads that it could upload on strategic delivery vehicles.

Russia has nonstrategic nuclear systems that do not fall under New START. The Obama, Trump, and Biden Administrations unsuccessfully sought to negotiate verifiable limits on these weapons, as per guidance in the Senate's 2010 resolution of New START ratification. U.S. officials have considered the possibility of an agreement that would cover all types of nuclear warheads, including those for nonstrategic nuclear weapons, though such an agreement would likely require intrusive verification measures. In 2023, President Putin stated that Russia had deployed nonstrategic nuclear weapons to Belarus.

Russia also has novel nuclear and nuclear-capable delivery vehicles that President Putin has said are intended to counter U.S. ballistic missile defenses. Russia included some of these—a new heavy ICBM and an ICBM-mounted hypersonic glide vehicle—in New START. Others, such as a nuclear-powered cruise missile and an autonomous underwater system, remain outside of an arms control framework. According to the U.S. intelligence community's unclassified 2025 Annual Threat Assessment, Russia is also "developing a new satellite meant to carry a nuclear weapon."

Arms control in a two-nuclear-peer environment

Congress may consider how U.S.-Russian nuclear arms control fits into in an environment where China's nuclear arsenal is expanding, with potential implications for U.S. deterrence requirements. According to a 2024 unclassified DOD assessment, China may have over 1,000 "operational nuclear warheads" by 2030. The Biden Administration's 2024 nuclear employment strategy argued that "the types of limits that the United States will consider," including in future negotiations with Russia, "will be influenced by the actions and trajectories of other nuclear-armed actors."

The 2023 report of the Congressional Commission on the Strategic Posture of the United States, which warned of an emergence of a "two-nuclear-peer" threat, argued that the United States needed to start with a strategy and appropriate nuclear force requirements prior to "developing U.S. nuclear arms control limits for the 2027-2035 timeframe." The Commission also stressed the need for research into verification technologies to support future arms control efforts and highlighted the potential importance of formal and informal risk reduction measures with both Russia and China "to increase predictability and reduce uncertainty."

In the absence of arms control, such measures, according to some experts, could range from data exchanges to operational constraints, such as political commitments to avoid interfering with NC3 or with monitoring by national technical means. Russia's willingness to discuss risk reduction is uncertain.

Role of Congress in arms control and risk reduction

Congress may consider what its role may be in future efforts to manage the risks of nuclear competition. In past Congresses, Members have debated, assessed, and conducted oversight of U.S.-Russian arms control and risk reduction measures and their contributions to U.S. national security. Some Members have proposed risk reduction measures for potential executive branch enactment. Others have served as official U.S. observers in arms control negotiations.

CRS Products

CRS In Focus IF10519, Defense Primer: Strategic Nuclear Forces

CRS In Focus IF12672, Russia's Nuclear Weapons

CRS In Focus IF12621, Congressional Commission on the U.S. Strategic Posture

CRS Report RL33865, Arms Control and Nonproliferation: A Catalog of Treaties and Agreements