[BBC] Ukraine is turning the tide against "exhausted" Russian forces, the head of Britain's GCHQ intelligence agency will say in a speech on Tuesday.Despite the missile attacks on targets across Ukraine on Monday, Sir Jeremy Fleming will claim Moscow is running out of ammunition.
North Korea agrees.
He will say President Vladimir Putin's decision-making has proved "flawed".
The intelligence chief will also assert that the UK and its allies are at a defining moment when it comes to China.
The director of the intelligence, cyber and security agency will say the costs to Russia of the war in Ukraine - in terms of both people and equipment - are "staggering" as early gains are now reversed.
"We know - and Russian commanders on the ground know - that their supplies and munitions are running out," Sir Jeremy will say in his speech at the annual Royal United Services Institute security lecture.
He will argue that the mobilisation of prisoners and inexperienced men "speaks of a desperate situation" - and will also directly criticise President Putin as isolated and making mistakes.
"With little effective internal challenge, his decision-making has proved flawed. It's a high stakes strategy that is leading to strategic errors in judgement."
Sir Jeremy also claims the Russian people are now starting to understand the problems caused by what he describes as Putin's "war of choice".
"With little effective internal challenge, his decision-making has proved flawed. It's a high stakes strategy that is leading to strategic errors in judgement."