A widening rift between Moscow and Washington over cruise missiles and increasingly daring patrols by nuclear-capable Russian submarines threatens to end an era of arms control and bring back a dangerous rivalry between the world’s two dominant nuclear arsenals.

Tensions have been taken to a new level by US threats of retaliatory action for Russian development of a new cruise missile. Washington alleges it violates one of the key arms control treaties of the cold war, and has raised the prospect of redeploying its own cruise missiles in Europe after a 23-year absence.

On Boxing Day, in one of the more visible signs of the unease, the US military launched the first of two experimental “blimps” over Washington. The system, known as JLENS, is designed to detect incoming cruise missiles. The North American Aerospace Command (Norad) did not specify the nature of the threat, but the deployment comes nine months after the Norad commander, General Charles Jacoby, admitted the Pentagon faced “some significant challenges” in countering cruise missiles, referring in particular to the threat of Russian attack submarines.

Those submarines, which have been making forays across the Atlantic, routinely carry nuclear-capable cruise missiles. In the light of aggressive rhetoric from Moscow and the expiry of treaty-based restrictions, there is uncertainty over whether those missiles are now carrying nuclear warheads.

The rise in tension comes at a time when the arms control efforts of the post-cold-war era are losing momentum. The number of strategic nuclear warheads deployed by the US and Russia actually increased last year, and both countries are spending many billions of dollars a year modernising their arsenals. Against the backdrop of the war in Ukraine and a failing economy, Vladimir Putin is putting increasing emphasis on nuclear weapons as guarantors and symbols of Russian influence. In a speech primarily about the Ukrainian conflict last summer, Putin pointedly referred to his country’s nuclear arsenal and declared other countries “should understand it’s best not to mess with us”.

The Russian press has taken up the gung-ho tone. Pravda, the former mouthpiece of the Soviet regime, published an article in November titled “Russian prepares a nuclear surprise for Nato”, which boasted of Russian superiority over the west, particularly in tactical nuclear weapons.

“The Americans are well aware of this,” the commentary said. “They were convinced before that Russia would never rise again. Now it’s too late.”

Some of the heightened rhetoric appears to be bluster. The new version of the Russian military doctrine, published on 25 December, left its policy on nuclear weapons unchanged from four years earlier. They are to be used only in the event of an attack using weapons of mass destruction or a conventional weapon onslaught which “would put in danger the very existence of the state”. It did not envisage a pre-emptive strike, as some in the military had proposed.

However, the new aggressive tone coincides with an extensive upgrading of Russia’s nuclear weapons, reflecting Moscow’s renewed determination to keep pace with the US arsenal. It will involve a substantial increase in the number of warheads loaded on submarines, as a result of the development of the multi-warhead Bulava sea-launched ballistic missile.

The modernisation also involves new or revived delivery systems. Last month Russia announced it would re-introduce nuclear missile trains, allowing intercontinental ballistic missiles to be moved about the country by rail so they would be harder to target.

There is also mounting western anxiety over Russian marketing abroad of a cruise missile called the Club-K, which can be concealed, complete with launcher, inside an innocuous-looking shipping container until the moment it is fired.

However, the development that has most alarmed Washington is Russian testing of a medium-range cruise missile which the Obama administration claims is a clear violation of the 1987 intermediate-range nuclear forces (INF) treaty, the agreement that brought to an end the dangerous standoff between US and Russian cruise missiles in Europe. By hugging the contours of the Earth, cruise missiles can evade radar defences and hit strategic targets with little or no notice, raising fears on both sides of surprise pre-emptive attacks.

At a contentious congressional hearing on 10 December, Republicans criticised two of the administration’s leading arms control negotiators, Rose Gottemoeller of the State Department and Brian McKeon of the Pentagon, for not responding earlier to the alleged Russian violation and for continuing to observe the INF treaty.

Gottemoeller said she had raised US concerns over the new missile “about a dozen times” with her counterparts in Moscow and Obama had written to Putin on the matter. She said the new Russian cruise missile – which she did not identify but is reported to be the Iskander-K with a reach in the banned 500-5,500km range – appeared to be ready for deployment.

The Russians have denied the existence of the missile and have responded with counter-allegations about American infringements of the INF treaty that Washington rejects.

McKeon said the Pentagon was looking at a variety of military responses to the Russian missile, including the deployment of an American equivalent weapon.

“We have a broad range of options, some of which would be compliant with the INF treaty, some of which would not be, that we would be able to recommend to our leadership if it decided to go down that path,” McKeon said. He later added: “We don’t have ground-launched cruise missiles in Europe now, obviously, because they are prohibited by the treaty but that would obviously be one option to explore.”

Reintroducing cruise missiles into Europe would be politically fraught and divisive, but the Republican majority in Congress is pushing for a much more robust American response to the Russian missile.

The US military has also been rattled by the resurgence of the Russian submarine fleet. Moscow is building new generations of giant ballistic missile submarines, known as “boomers”, and attack submarines that are equal or superior to their US counterparts in performance and stealth. From a low point in 2002, when the Russian navy managed to send out no underwater patrols at all, it is steadily rebounding and reasserting its global reach.

There have been sporadic reports in the US press about Russian submarines reaching the American east coast, which have been denied by the US military. But last year Jacoby, the head of Norad and the US northern command at the time, admitted concerns about being able to counter new Russian investment in cruise missile technology and advanced submarines.

“They have just begun production of a new class of quiet nuclear submarines specifically designed to deliver cruise missiles,” Jacoby told Congress.

Peter Roberts, who retired from the Royal Navy a year ago after serving as a commanding officer and senior UK liaison officer with the US navy and intelligence services, said the transatlantic forays by Akula-class Russian attack submarines had become a routine event, at least once or twice a year.

“The Russians usually put out a sortie with an Akula or an Akula II around Christmas … It normally stops off Scotland, and then through the Bay of Biscay and out over the Atlantic. It will have nuclear-capable missiles on it,” he said.

Roberts, who is now senior research fellow for sea power and maritime studies at the Royal United Services Institute, said the appearance of a periscope off the western coast of Scotland, which triggered a Nato submarine hunt last month, was a sign of the latest such Russian foray.

He said the Russian attack submarine was most likely heading for the US coast. “They go across to eastern seaboard, usually to watch the carrier battle groups work up [go on exercises].

“It’s something the Americans have been trying to brush off but there is increasing concern about the American ability to … track these subs. Their own anti-sub skills have declined, while we have all been focused on landlocked operations, in Afghanistan and so on.”

The Akula is being superseded by an even stealthier submarine, the Yasen. Both are multipurpose: hunter-killers designed to track and destroy enemy submarine and carrier battle groups. Both are also armed with land-attack cruise missiles, currently the Granat, capable of carrying nuclear warheads.

On any given sortie, Roberts said, “it is completely unknown whether they are nuclear-tipped”.

A Russian media report described the Akula as carrying Granat missiles with 200-kilotonne warheads, but the reliability of the report is hard to gauge.

The US and Russia removed nuclear cruise missiles from their submarines following reciprocal presidential initiatives in 1991. In declarations at the time of the Strategic Arms Reduction treaty (Start) in the same year, the two countries also agreed to exchange data on deployed sea-launched nuclear cruise missiles for the next five years. The successor treaty, New Start, signed by Obama and the then Russian president, Dmitry Medvedev in 2010 does not include any such reporting obligation. So both sides are now in the dark about what is on each other’s attack submarines.



Pavel Podvig, a senior research fellow at the UN Institute for Disarmament Research and the leading independent analyst of Russian nuclear forces, said: “The bottom line is that we don’t know, but it’s safe to say that it’s quite possible that Russian subs carry nuclear SLCMs [submarine-launched cruise missiles].

Jeffrey Lewis, an arms control expert at the Monterey Institute of International Studies and founding publisher of ArmsControlWonk.com, believes the JLENS blimps are primarily a response to a Russian move to start rearming attack submarines with nuclear weapons.

“For a long time, the Russians have been saying they would do this and now it looks like they have,” Lewis said. He added that the fact that data exchange on cruise missiles was allowed to expire under the New Start treaty is a major failing that has increased uncertainty.

The Russian emphasis on cruise missiles is in line with Putin’s strategy of “de-escalation”, which involves countering Nato’s overwhelming conventional superiority with the threat of a limited nuclear strike that would inflict “tailored damage” on an adversary.

Lewis argues that Putin’s accentuation of Russia’s nuclear capabilities is aimed at giving him room for manoeuvre in Ukraine and possibly other neighbouring states.

“The real reason he talks about how great they are is he saying: ‘I’m going to go ahead and invade Ukraine and you’re going to look the other way. As long as I don’t call it an invasion, you’re going to look at my nuclear weapons and say I don’t want to push this,’” he said.

With both the US and Russia modernising their arsenals and Russia investing increasing importance its nuclear deterrent, Hans Kristensen, the director of the Nuclear Information Project at the Federation of American Scientists, said we are facing a period of “deepening military competition”.

He added: “It will bring very little added security, but a lot more nervous people on both sides.”

• This article was amended on 7 January 2015 to clarify that an agreement between the US and Russia to remove nuclear cruise missiles from their submarines was part of reciprocal presidential initiatives in 1991.