By Mark Trevelyan
LONDON, Jan 8 (Reuters) - Even at the height of their Cold War nuclear rivalry, the United States and the Soviet Union thrashed out a series of treaties to keep the arms race from spiralling out of control.
Though they agreed on little else, leaders in Moscow and Washington saw value in talks - from 1969 until long after the Soviet collapse in 1991 - to create a stable and predictable framework limiting the size of their nuclear arsenals.
Now the last U.S.-Russia nuclear treaty, New START, is just weeks away from expiring on February 5, and what comes next is uncertain. The two countries, preoccupied by the war in Ukraine, have not held any talks on a successor treaty.
Russian President Vladimir Putin proposed in September that both parties should agree for a further 12 months to adhere to the New START limits, which cap the number of deployed nuclear warheads at 1,550 on each side.
U.S. President Donald Trump has yet to deliver a formal response, and Western security analysts are divided about the wisdom of accepting Putin's offer.
On the one hand, it would buy time to chart a way forward, while sending a political signal that both sides want to preserve a vestige of arms control.
On the other hand, it would allow Russia to keep developing weapons systems outside the scope of New START, including its Burevestnik cruise missile and Poseidon torpedo. Former U.S. defence planner Greg Weaver noted in a paper for the Atlantic Council that Russia had refused since 2023 to accept mutual inspections that would provide Washington with assurances that Moscow is still complying with the treaty.
Agreeing to Putin's proposal, Weaver added, would also send a message to China that the United States would not build up its strategic nuclear forces in response to China's fast-growing nuclear arsenal.
"This signal would likely undermine the prospects for bringing China to the arms control negotiating table, indicating to China that US forces will remain limited regardless of what China does."
TRUMP WANTS TALKS WITH RUSSIA AND CHINA, BEIJING SAYS NO
Russia and the United States have estimated total inventories of 5,459 and 5,177 nuclear warheads respectively, according to the Federation of American Scientists. Between them they account for nearly 87% of all such warheads globally.
China, however, has accelerated its nuclear programme and now has an estimated 600 warheads. The Pentagon estimates it will have more than 1,000 by 2030.
While Trump has stated he wants to pursue "denuclearisation" with both Russia and China, Beijing says it is "unreasonable and unrealistic" to ask it to join three-way nuclear disarmament talks with countries whose arsenals are so much larger.
Further complicating the prospects for global arms control, Russia says the nuclear forces of NATO members Britain and France should also be up for negotiation - something those countries reject.
Nikolai Sokov, a former Soviet and Russian arms negotiator, said in a telephone interview that trying to forge a new multilateral nuclear treaty in this environment was "almost a dead end. It will take forever."
Sokov, a senior fellow at the Vienna Center for Disarmament and Non-Proliferation, said one alternative would be for Russia and the U.S. to work out a successor to New START that would include flexible warhead limits to take account of the Chinese build-up.
But a faster and more straightforward course would be for countries to focus on steps to reduce the significant risk of a nuclear war breaking out by accident. Right now, for example, only Russia and the U.S. have a 24/7 hotline for use in a nuclear crisis, whereas "no European capital, not even the NATO headquarters, can actually communicate with Moscow. There is no dedicated line," Sokov said.
"If parties at the same time also begin negotiations on arms control, that would be great. But you need to understand that the next treaty will be very, very complex... It will take time. So the number one priority is risk reduction and confidence building," he added.
(Reporting by Mark Trevelyan; editing by Philippa Fletcher)
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