The U.S. has set goals for a new strategic U.S.-Russian nuclear arms control treaty when the current one, known as New START, expires in 2026. In February 2023, Russia suspended its participation in New START, but has not withdrawn from the treaty.
The goals are to ensure that a new treaty addresses all nuclear weapons—including those in storage and shorter-range weapons—and certain weapon delivery vehicles. For the next treaty, officials largely expect to use current methods to verify that each country complies, such as on-site inspections and satellite imagery.
Beyond the next treaty, future treaties could include more extensive nuclear weapon limits. Verifying such treaties may require more advanced technology, which the U.S. is researching and developing.
The Government Accountability Office (GAO) has found that the U.S. has established three goals for a nuclear arms control treaty with Russia to follow New START:
- Retain limits on systems capable of delivering nuclear weapons at intercontinental ranges, or “strategic delivery vehicles”;
- Address all nuclear weapons, including nonstrategic nuclear weapons and weapons in storage; and
- Address new and novel Russian delivery vehicles, such as a nuclear-powered and nuclear-armed cruise missile.
According to U.S. officials, the measures for verifying compliance with a New START successor are likely to be similar to those employed for New START, including exchanges of data about deployed strategic delivery vehicles, inspections at relevant bases, and use of satellites. In the long term, the U.S. has aspirational goals—such as nuclear weapons reductions—that may require more extensive verification using more intrusive technologies.
The National Nuclear Security Administration (NNSA) has a plan for developing verification technologies that would support an array of possible treaty scenarios. NNSA’s plan groups these technologies into three “approaches” based on increasing levels of intrusiveness and confidence in compliance. Officials told GAO that technologies in the first, “baseline” approach are largely proven or already used under New START and are ready to support a potential successor treaty. More intrusive technologies—such as devices to measure weapons’ radiation signatures—would provide increased confidence in compliance and support longer-term treaty goals but may require 5 to 10 more years of development.
Stakeholders GAO interviewed and studies GAO reviewed noted likely challenges to verifying Russian compliance with future treaties that address U.S. nuclear arms control goals. For example, nuclear weapons are smaller than strategic delivery vehicles and would thus be harder to monitor using satellites. Verifying Russian compliance with limits on nonstrategic nuclear weapons may also be challenging, in part because many Russian nonstrategic delivery vehicles can carry nuclear or conventional weapons, making visual differentiation difficult.
GAO says the U.S. seeks to engage China in preliminary discussions that could lead to future nuclear arms control negotiations. However, the watchdog found that the U.S. has not specified goals for an arms control treaty with China.
In 2021, the Secretary of State said that the U.S. seeks to pursue nuclear arms control with China to reduce the dangers associated with China’s expansion and modernization of its nuclear forces. According to State officials who spoke with GAO, however, sustained nuclear dialogue and arms control discussions have not occurred yet. According to these officials, as well as several stakeholders GAO interviewed and studies it reviewed, a formal nuclear arms control agreement between the U.S. and China is unlikely in the near future for several reasons.
First, according to some stakeholders and studies, China is not interested in limits on its nuclear forces until it attains some degree of nuclear force parity with the U.S. According to the 2023 Annual Threat Assessment of the U.S. Intelligence Community, China is developing hundreds of new ICBM silos and is reorienting its nuclear posture for strategic rivalry with the U.S. However, China has significantly fewer nuclear weapons than the U.S. and is unlikely to achieve numerical parity for many years.
Second, some stakeholders told GAO that, in contrast to the long history of arms control negotiations between the U.S. and Russia and the Soviet Union, China and the U.S. have no history of nuclear arms control negotiations. These stakeholders also said that China does not prioritize the kind of transparency measures included in nuclear arms control agreements, such as New START. By contrast, the U.S. and Russia (and previously the Soviet Union) have had about 50 years of such experience.
For these reasons, several stakeholders told GAO it would be more feasible for future negotiations to be preceded by preliminary U.S.-China discussions that could build Chinese confidence in the benefits of arms control and transparency. For example, one State official said that establishing a form of crisis communication line could be a productive first step in confidence building.
NNSA officials told GAO that there are no known technological verification challenges unique to China. As a result, they believe that the verification measures NNSA has developed or is developing to support a treaty with Russia would likely be applicable to any verification regime for a future treaty with China.