China

I think [Prime Minister Takaichi] she is quite determined about Japan's security and defence, but she has no aggressive intentions regarding China and Taiwan. But I think you're right about having unsettled Beijing because...Prime Minister Takaichi, even before she reached this level, had expressed opinions about Japan's history which don't have the same sort of regret and shame and reflections on Japanese aggression as they would like to hear in Beijing, and that's something that they expect. So that was one thing. The comments she made about Japan being affected by a potential conflict between China and the US over Taiwan added to that and quickly spiralled into a kind of quite virulent attack on her and on the idea of Japanese militarism or remilitarisation. So yes, they are unsettled. And this election result, where despite the people you were interviewing in Japan, obviously a lot of the electorates in Japan did support her leadership. So I think that that must get across in Beijing a message that Prime Minister Takaichi is not unrepresentative in having these strong feelings about Japan."

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.

Some of the drivers that are relevant here, in terms of thinking about how big of an arsenal the U.S. might actually want, have to do with the deterrence of attacks against the United States themselves, against US territory, but also the ability of the US to extend deterrence to its allies in Europe and elsewhere, and to be able to do that. The US needs to, for instance, make credible the fact that it could carry out effective damage limitation strikes against Russia's nuclear capabilities, and that it has a survivable second strike capability following any Russian retaliation. So there are a couple of different drivers, again, that go into calculating the numbers that the United States might want on the part of the Russians in similar considerations, although they don't have the same extended deterrence commitments that the United States has. But in Russia, strategic culture also plays an important role, as it does in other states, but in the case of Russia and the Soviet Union before it, they very much see themselves as a leading world power and a leading power that needs to have parity with the United States when it comes to its nuclear arsenal. So that's also been an important driver of the high numbers of systems for Russia."