A key Cold War-era nuclear arms treaty has died. What does that mean for the world?

The end of a historic pact between the US and Russia, which eliminated a whole category of nuclear and conventional missiles and vastly reduced the chances of Europe become a combat arena for the two superpowers, has brought fresh uncertainty and concerns about a new arms race.

The Intermediate-Range Nuclear Forces (INF) Treaty banned the use of all land-based short and medium missiles, with nearly 2,700 of them being decommissioned, and gave the two sides unprecedented access to each other’s arsenals for inspections.

Its signing, between Ronald Reagan and Mikhail Gorbachev in 1987, was also hugely symbolic in highlighting the thaw in the Cold War. The US president had announced that he no longer saw the Kremlin as the centre of an “evil empire” and Margaret Thatcher declared that the Russian leader was a man the west “could do business with”.

Despite the repeated allegations that Donald Trump was the Moscovian Candidate for the White House in the presidential election, and his apparent tendresse for Vladimir Putin, the increasing acrimony between the two countries on matters of arms control and weaponry has not ended under the current US administration.

Six months ago, Mr Trump set 2 August as the deadline for the US to withdraw from the INF if Moscow did not draw back from moves which, Washington claimed, did not comply with its terms. On 3 July, under an order signed by President Putin, Russia suspended its participation in the Treaty.

There had been allegations of non-compliance by both sides in the past. But the issues came to a head at the start of this year when the US and Nato accused Russia of violating the pact with the deployment of 9M729 missiles – SSC-8 in Nato code – a cruise missile.

Moscow denied the charge and claimed that the west was trying to find a way to renege on the treaty. It held that the deployment of American anti-missile defence systems, which can be reconfigured to fire intermediate-range missiles, was in itself a breach of the terms.

The US secretary of state blamed Moscow for the breakdown of INF: “Russia is solely responsible for the treaty’s demise. With the full support of our Nato allies, the United States has determined Russia to be in material breach of the treaty,” said Mike Pompeo.

“Russia failed to return to full and verified compliance through the destruction of its noncompliant missile system and thus we have suspended our obligations.”

The UK’s latest foreign secretary, Dominic Raab, tweeted: “Russia has caused the INF treaty to collapse by secretly developing and deploying a treaty-violating missile system which can target Europe’s capitals. Their contempt for the rules-based international system threatens European security. UK fully supports Nato’s response”.

Russia’s deputy foreign minister, Sergei Ryabkov, insisted that the treaty had been terminated “at the initiative of the US”. He asked for Washington to agree to a moratorium on deployment of short- and intermediate-range nuclear missiles in Europe.

The call, according to Nato secretary general Jens Stoltenberg, was spurious: “This is not a credible offer because Russia has deployed missiles for years. There is zero credibility in offering a moratorium on missiles they have already deployed.”

The Russian cruise missiles, Mr Stoltenberg wanted to stress, could “reach EU cities, with only minutes of warning time … they were mobile capable, hard to detect, and would lower the threshold for the use of nuclear weapons in armed conflict”.

Mr Stoltenberg held that Nato would “respond in a measured and responsible way to the significant risks posed by the Russian 9M729 missile to allied security”.

The alliance, however, “does not want a new arms race”, he added, and pointed out there were no plans for the alliance to deploy land-based nuclear missiles of its own in Europe.

The Pentagon has been working on a mobile launch system within the restrictions of the INF. The Trump administration’s budget request for fiscal year 2020, released in February – the same month the president gave notice to Russia over the treaty – included $96m (£79m) for continued research and development on missiles.

The planning was within the INF strictures, but with the treaty gone, the programme can be modified.

The UN secretary general, Antonio Guterres, has warned that the end of INF means “the world will lose an invaluable brake on nuclear war. This will likely heighten, not reduce, the threat posed by ballistic missiles.”

He urged the US and Russia to “urgently seek agreement on a new common path for international arms control”.

One man who found such a common path, Mikhail Gorbachev, also had foreboding about the future. The former Russian leader, now aged 88, said in Moscow that one had expected the differences between the two sides to be resolved, and spoke of the consequences of that not happening.

“There still were some hopes pinned on our partners that, unfortunately, did not materialise. We can now all see, I think, that a blow has been dealt to strategic security.”

Another landmark pact of the Cold War, the New Start Treaty, which limits long-range nuclear weapons, is set to expire in February 2021.

Mr Gorbachev called on all parties to “focus on the preservation of the last pillar of the global strategic security”.

But that looks far from certain. John Bolton, the superhawk national security advisor to Mr Trump, has made his position clear. The treaty, he holds, is “flawed” and “unlikely to be extended … Why extend a flawed system just to say you have a treaty?”