The last nuclear weapons control treaty between the US and Russia has expired, raising fears of a new arms race.

The Strategic Arms Reduction Treaty, known as “New START” and signed in 2010, was one of a handful of agreements designed to help prevent a catastrophic nuclear war.

UN Secretary General António Guterres has said its end “marks a grave moment for international peace and security” and called on Russia and the US to negotiate a successor framework “without delay”.

Its expiry, at midnight GMT, effectively marked an end to the arms control co-operation between Washington and Moscow that helped bring an end to the Cold War.

The treaty had capped the number of deployed strategic nuclear warheads for each party to 1,550 and established some transparency including data transfer, notifications and on site inspections.

Without it, Guterres warned, “we face a world without any binding limits on the strategic nuclear arsenals” of the countries that possess the “overwhelming majority of the global stockpile of nuclear weapons”.

He called on the two states to “reset and create an arms control regime fit for a rapidly evolving context” as the “risk of a nuclear weapon being used is the highest in decades”.

Guterres said he welcomed that both US President Donald Trump and Russian President Vladimir Putin had made clear they

appreciate the need to prevent “unchecked nuclear proliferation” but urged them to “translate words into action”.

On Wednesday, Pope Leo also urged the two states to renew the treaty, saying the current world situation required “calls for doing everything possible to avert a new arms race”.

The original Start treaty - signed in 1991 by the US and the Soviet Union - barred each of the two signatories from deploying more than 6,000 nuclear warheads.

It was succeeded by New Start signed in 2010 in Prague by the US and Russia, the successor state to the dissolved Soviet Union.

Although Russia suspended the treaty three years ago as tensions grew over the Ukraine war, both countries were still thought to be abiding by the treaty.

The agreement prevented the uncontrolled build-up of nuclear weapons and provided the two countries with the largest nuclear arsenals with transparency measures to avoid misjudging each other’s intentions.

Its expiry follows a worrying pattern. Other long-standing arms control treaties have already fallen by the wayside.

They include:

• The Intermediate-Range Nuclear Forces Agreement, which largely eliminated the deployment of shorter-range nuclear weapons within Europe
• The Open Skies Treaty, which allowed signatories, including the US and Russia, to fly unarmed reconnaissance flights over each other’s territory to monitor military forces
• The Conventional Armed Forces in Europe Treaty, which limited the numbers of tanks, troops and artillery systems both Russia and Nato forces could deploy within Europe
• 
  

Britain’s former head of the armed forces, Admiral Sir Tony Radakin has warned that the architecture and frameworks that helped keep the world safe “now risks unravelling”.

In a speech last year he described the collapse of these key arms control treaties as “one of the most dangerous aspects of our current global security”, along with “the increasing prominence of nuclear weapons”.

Russia’s Dmitry Medvedev, who as the then president signed the New Start treaty in 2010, said its expiration should “alarm everyone”. This is a sobering comment from a politician whose recent rhetoric has included nuclear threats.

On Wednesday, a senior adviser to Russian President Vladimir Putin said he intended to “act in a measured manner and responsibly” if the treaty expired.

Later in the day, the Russian foreign ministry said in a statement that “in the current circumstances, we assume that the parties to the New START are no longer bound by any obligations or symmetrical declarations in the context of the Treaty, including its core provisions, and are in principle free to choose their next steps.

“In doing so the Russian Federation intends to act responsibly and in a balanced manner,” the statement said, adding that Moscow “remains ready to take decisive military-technical measures to counter potential additional threats to the national security”.

US President Donald Trump has sounded less concerned. Last month, he told the New York Times: “If it expires, it expires… We’ll just do a better agreement”.

Washington believes that any future arms control treaty should also include China, which has been building up its nuclear arsenal.

This sentiment was echoed by German Foreign Minister Johann Wadephul on Thursday, who told reporters in Canberra “China has to be included”.

China “keeps emphasising that they stand with multilateralism, they also have to show in the field of arms control that they are ready to show restraint and that they invest trust in international relations”, he added.

Meanwhile, Russia has long argued that any future arms control treaty should include France and the UK - Europe’s nuclear powers.

Darya Dolzikova, a senior Research Fellow with the UK-based RUSI’s Proliferation and Nuclear Policy Programme, said the expiration of New Start was “concerning, because there are drivers on both sides to expand their strategic capabilities”.

Both the US and Russia are currently modernising their nuclear forces and increasing their strategic capabilities. A new arms race is already under way.

Dolzikova said that for Russia “there appears to be some concerns about their ability to penetrate US air defences”. This has only increased with Trump’s plans to build a “Golden Dome” to protect North America from long-range weapons.

But Russia has also been developing new weapons designed to overcome air defences.

They include Poseidon - a new intercontinental, nuclear armed and nuclear powered undersea autonomous torpedo, and also Burevestnik – a nuclear armed and powered cruise missile.

The US, Russia and China are all developing long-range hypersonic missiles which can manoeuvre at speeds of more than 4,000 mph (6,437kmh), and are much harder to shoot down.

Dolzikova said those expanding military capabilities would “only make it harder” to reach a new arms control treaty.

This is along with what she called the “growing salience of nuclear weapons”. More, not fewer, countries appear to want them as a deterrent.

Nor does the US or Russia appear to be in a rush to sign a new arms control treaty.

The subject was on the agenda when Russian President Vladimir Putin met Trump in Alaska last year - but nothing happened.

A new deal is still possible - but the expiry of the New Start signals a more volatile, dangerous era.

Source: BBC