The New START Treaty, negotiated in 2010, restricts the strategic nuclear arsenals of the United States and Russia. It is the only such treaty remaining in force.

The treaty is due to expire on 5 February 2021. It can be extended for up to five years if both parties agree. If it does expire and no successor agreement has been negotiated, it will be the first time since 1972 that there will have been no quantitative limit on US and Russian nuclear stockpiles.

This Insight examines the current nuclear restrictions under New START and the prospects for future arms control.

A brief history of bilateral arms control

After the Cuban Missile Crisis, and throughout the 1960s, there was mounting concern about the rapid expansion in the number of nuclear warheads and delivery systems. In response, bilateral talks aimed at restricting the nuclear arsenals of the Soviet Union and the US began. Over the decades that followed, a series of arms control regimes emerged.

In August 2019 the US officially withdrew from the Intermediate-Range Nuclear Forces Treaty. As a result, the New START Treaty is the only one in force which limits the size of US and Russian nuclear arsenals.

What was agreed?

Under the terms of New START the US and Russia agreed to a maximum of 1,550 strategic operationally deployable warheads. They also agreed to a combined limit of 800 deployed and non-deployed intercontinental ballistic missile launchers, submarine launched ballistic missile launchers and heavy bombers equipped for nuclear armaments. It did not address non-strategic (tactical) nuclear weapons.

New START also established a verification regime that combines various elements of the original START verification regime, established in 1991, and measures tailored to the current treaty.

Both countries are in compliance with their treaty obligations.

How many nuclear weapons does each party have?

The US has approximately 3,800, and Russia has 4,315 operational nuclear warheads (strategic, non-strategic and reserve). A further 2,000 US and 2,060 Russian warheads are awaiting dismantlement.

What next for nuclear arms control?

The US and Russian Presidents have the opportunity to either extend the treaty up to 2026, negotiate a successor agreement to achieve further reductions in their nuclear arsenals, or let the treaty lapse.

If the New START Treaty expires in February 2021, and is not replaced by a successor treaty, there will be no limits on the strategic nuclear forces of the two largest nuclear weapon states. This would be the first time in nearly 50 years that the world will face such a scenario.  

That prospect has prompted fears of a fresh quantitative nuclear arms race. It will also leave the US and Russia with fewer tools to verify the size and composition of each other’s nuclear arsenals.

Observers have also argued that it will leave both countries in violation of their disarmament obligations under Article VI of the Nuclear Non-Proliferation Treaty.

Views on extension

Russia has expressed its unconditional support for extending New START and has agreed to discuss potential future arms control. The US, on the other hand, has kept its options open.

President Trump has stated his desire to see a “grand bargain” in future arms control. He wants to see a move beyond the traditional bilateral approach that includes China in future negotiations.

He also wants any future agreement to encompass a wider variety of nuclear weapons. This would include Russia’s arsenal of non-strategic nuclear weapons and new delivery systems it has under development. The US administration has linked progress on such issues with any US agreement on New START extension.

Talks are ongoing

The latest round of US-Russian strategic stability talks took place on 22 June 2020. No agreement on New START was reached. However, both sides agreed to establish working groups on several key issues. A further round of dialogue is anticipated in August 2020.

Concerns have been expressed about the talks’ prospects for success. New START expires in just six months. Russia is unlikely to agree any curbs on its non-strategic nuclear capabilities, or the new systems it has under development unless the US places missile defence and US non-strategic nuclear weapons in Europe, on the table for discussion. China has also declined the invitation to participate in talks, highlighting the huge disparity between its nuclear stockpile (320 warheads) and that of Russia and the US.

Is extension a possibility?

Many experts favour extending the treaty, while arms control negotiators pursue a new multilateral agreement. This approach is supported by Russia, NATO allies and many members of the US Congress and the US military.

Much will depend on how the US administration views progress in the next few months, and whether President Trump wins a second term in November 2020.

If Trump is re-elected and the treaty allowed to lapse with no successor agreement in place, then he will be the first sitting US President since Richard Nixon not to have engaged in, or agreed to, meaningful arms control restrictions with Russia.

If the Democrats win the election in November 2020, they will have little more than two weeks after the inauguration of the new President in January 2021 in which to change course.

Further reading

Prospects for US-Russian nuclear arms control, House of Commons Library.

About the author: Claire Mills is a researcher at the House of Commons Library specialising in defence.

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