Britain would expect to see indicators if Russia was starting to consider deploying its nuclear arsenal in its war with Ukraine, Britain's top cyber spy said on Tuesday, repeating that any talk of using such weapons was highly dangerous.
After more than seven months of war, Jeremy Fleming, director of the GCHQ spy agency, told BBC Radio that Russia was running short of munitions, friends and troops.
Russian President Vladimir Putin has so far stayed within established military doctrine of not using nuclear weapons, Fleming said, but his agency would be looking out for signs that this could change.
"I would hope that we will see indicators if they started to go down that path," he said, without saying what those indicators could be.
"But let's be really clear about that, if they are considering that, that would be a catastrophe in the way that many people have talked about".
Fleming also said he was sure Putin was worried about the dangers of escalation and that might be a sign of why "he has not reached for these other forms of waging war".
In a speech due to be delivered later on Tuesday, Fleming will also say that Russians were beginning to understand the desperate situation Moscow is in over the conflict.
"They're seeing just how badly Putin has misjudged the situation," he will say, according to excerpts from his speech.
"They're fleeing the draft, realising they can no longer travel. They know their access to modern technologies and external influences will be drastically restricted. And they are feeling the extent of the dreadful human cost of his war of choice."
(Reporting by Sachin Ravikumar, Kylie MacLellan, Kate Holton, Michael Holden and Elizabeth Piper, Editing by Andrew Cawthorne)
