Live updates: follow the latest news on Russia-Ukraine
Britain's most senior military officer, Admiral Sir Tony Radakin, has said the Russian leadership was deceived by its own over the competence and readiness of its armed forces to wage an offensive war in Ukraine.
With Russian tactics changing on the battlefield, Ukraine's allies are scrambling to assess how President Vladimir Putin is working out the next steps in the five-week campaign, which has not yet achieved any of the objectives outlined by Moscow.
“He allowed himself to be misled as to his own strength, including the effectiveness of the Russian armed forces,” Admiral Radakin, the chief of the UK Defence Staff, told the Institute for Government think tank.
“It was in particular astounding to learn that Russian forces had not been told they were being dispatched to Ukraine in an offensive to seize parts of the country. That was having consequences for how the ranks were performing in the conflict.”
Admiral Radakin added that this could be seen “at the most junior level, which is shocking in a professional sense”, with Russian officers taking soldiers into combat without them even knowing they were about to fight.
He said: “It seems an insane thing to do professionally and it’s a morally bankrupt thing to do for any individual. And then as you carry on up through the system, we’re also seeing the pressure that exists with, whether it is their tactical and operational level commanders — and their plans haven’t gone well.”
He said that Russia's most senior commanders are under pressure due to Moscow making such a “catastrophic mistake” and “the way it has prosecuted, the invasion looks to us like it has been very poorly conducted".
Western officials also pointed out that the failure to capture Russian-speaking towns in Ukraine that were on the target list has also had an impact at home and seems to have triggered adjustments in the Kremlin's tactics.
“It looks as if they at least do understand that they are taking heavy losses, but they must understand that they haven't taken care of even Russian-speaking towns,” one official said.
“I think at least he must be seeing more of the real information than ordinary Russians are able to see on their television screens.”
The insularity of Mr Putin has had significance as to how things are playing out.
“He's been in power a long time,” the official said. “He has a relatively small group of people around him. They're all pretty similar, from pretty similar backgrounds. You can also see how the echo chamber around him might very well reinforce his opinions, rather than challenge or debate.”