With Russia advancing on the Ukrainian capital, Kyiv, FactCheck readers are asking us two important questions.
Could the UK and its Western allies end up at war with Russia? And how close – or not – are we to a possible nuclear conflict?
Let’s take a look.
Could the West go to war with Russia?
Ukraine is not a member of NATO, the military alliance that includes Britain and the US.
That’s key because NATO rules say that an attack on one member is an attack on all.
If Ukraine had been part of the bloc, Russia’s invasion this week would have been considered an assault on all 30 NATO countries (though whether he’d have gone ahead with the invasion under those circumstances is another question.)
Western nations have been providing indirect support to Ukraine without actually deploying troops or declaring war on Russia. (Ukrainian leaders have been very critical of what they say is a feeble response from their allies.)
But if Vladimir Putin decides to take the fight beyond Ukraine and launch an assault on a NATO member – targeting, for example, nearby Poland, Latvia, Estonia, or Lithuania – this could all change.
If a member state is attacked, it can invoke Article 5 of the NATO treaty, known as the “collective defence” clause. That means it’s entitled to assistance from the other nations in the alliance.
So would that mean the UK going to war with Russia? Not necessarily.
Dr Kenton White, lecturer in strategic studies and international relations at the University of Reading, explained to FactCheck that invoking Article 5 “does not guarantee that all the other NATO states would send their armed forces.”
“The Article is quite explicit that military action is an option which can be included in response to an attack,” he added (his emphasis).
We can see this in the broad wording of the treaty, which says each state will take “such action as it deems necessary, including the use of armed force” to protect the country that has been attacked.
So strictly speaking, even if Russia did attack a NATO member, the UK would not be required to declare war or send soldiers.
Though, giving his personal view, Dr White says he “would expect Britain to honour its obligation to fight”.
Elena Korosteleva, professor of international politics at the University of Kent, told FactCheck that she believes Russia is “unlikely to attack any NATO member states, as it would be a step too far, which would result in WWIII.”
Mark Webber, professor of international politics at the University of Birmingham, told FactCheck that while there is a “danger of escalation”, his “expectation/hope is that Russia is very well aware of the danger of any such action and would desist.”
Are we at risk of nuclear war?
Russia has nuclear weapons, but Ukraine does not – it gave them up in 1994.
Professor Webber explains that “nuclear war only becomes imaginable if Russia and NATO enter into direct conflict.”
But even if there was such a conflict, that doesn’t automatically mean it’ll go nuclear.
That’s because of a principle called “mutual assured destruction”. The phrase was coined in the Cold War, when the Soviet Union and the US competitively built up their nuclear stocks.
The idea is that if one country launches a large-scale nuclear attack on another, it’s effectively a suicide mission because both nations will end up obliterated through retaliation and counter-retaliation.
That prospect is so dire that, the thinking goes, even countries that have nuclear weapons will never end up using them – so long as their enemies have roughly equivalent arsenals too.
That’s the theory as it applies to “strategic” nuclear weapons – the large missiles that, if they’re used, are intended to secure some long-term overarching objective like ending a war.
But what about “tactical” nuclear weapons? These are smaller devices designed to aid one side in a short-term battle situation, where the doctrine of mutual assured destruction doesn’t apply.
Dr White said he “would not expect Russia to use tactical nuclear weapons whilst invading Ukraine.”
There is, he says, “no need, and it would immediately turn Russia into an international pariah, far worse than a conventional attack.”
“I don’t believe China would be willing to support their use by Russia,” he added.
However, Dr White says, if “President Putin’s expansion over-reaches itself with an invasion of the Baltic States [Estonia, Latvia, Lithuania]” there is a possibility that he might use tactical nuclear weapons to avoid defeat.
Nevertheless, we are a long way from this hypothetical scenario.
The UK and Russia would only end up at war if Russia attacks a NATO member and the UK decides to respond with military might.
As Ukraine is not part of NATO, the UK has no obligation to make any military intervention so long as the fighting stays where it is.
And we should stress: Russia has not yet attacked any NATO member and might never do so.
Even if it did launch an assault, there’s no guarantee that the rest of NATO would declare war or take military action in response.
And even if NATO members did retaliate with force, there are plenty of barriers – not least the prospect of mutual assured destruction and major loss of life on both sides – to prevent any country involved in a hypothetical future NATO-Russia war from deploying nuclear weapons.