Russia

Some further measures could be helpful, said Kaushal, the naval analyst, deploying more unmanned surface vessels to keep track of Russian submarines and filling the shortage of sonar operators at sea. But a standing maritime presence in the Arctic would be “entirely superfluous” and even dangerous, Kaushal said. “That places vessels potentially in very difficult climates near Russian-held territory, where the only support infrastructure is Russian.”

Gonzalo Saiz Erausquin, a research fellow at the Royal United Services Institute, said Nordic and Baltic states had already been detaining vessels prior to the recent seizures, but that “this heightened environment creates momentum to sustain these actions...Whilst the detention of the Baltic Spirit was based on drug smuggling-related suspicions and not shadow fleet activity, vessel interceptions are gaining traction across Europe and we should expect more to follow."

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". 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.