Putin had been led to expect a quick and easy victory over Ukraine by his intelligence and military chiefs, analysts believe. The Russian leader is thought to have expected minimal resistance from Ukrainians and loyalists willing to back a Kremlin-installed puppet government.
However, Russian forces have faced strong resistance from both Ukrainian troops and civilians which has left the invasion floundering.
The latest intelligence briefing from the UK Ministry of Defence said Russia had suffered “considerable losses” in Ukraine, while NATO estimated Moscow has lost as much as a fifth of its combat forces a month into the war.
Putin is reportedly aiming most of the blame for the struggling invasion at the FSB, Russia’s domestic security agency, which the panicked leader believes has been infiltrated by spies.
Putin has placed two commanders from the Fifth Service of the FSB under house arrest, Business Insider reported.
Andrei Soldatov, an investigative journalist and expert on Russian security services, told the publication that Sergei Beseda and his deputy had been detained in the past week.
One of the fifth department’s responsibilities is liaising with the CIA, making it “the first place to look for Western spies”, according to Mr Soldatov.
He said the pair were responsible for areas like political subversion and building local networks to back the Ukraine invasion.
Meanwhile, the Russian military’s counterintelligence division has launched an investigation to identify possible spies and foreign agents in the FSB, according to Mr Soldatov’s sources.
He said: “What we see in Moscow is a sense of desperation in terms of the lack of political support in Ukraine for the invasion.”
Mr Soldatov said the fact that Western intelligence reports have contained details of Russia’s military buildup, plans and difficulties with the invasion has sparked fears in the Kremlin that the FSB may have been infiltrated by foreign intelligence.
Moscow has reportedly become increasingly suspicious that spies have been feeding information of its military plans to the West.
Mr Soldatov said that, in Russia, “we have the military counterintelligence looking into the activities of the fifth department of the FSB, which basically means that they started looking for moles because military counterintelligence is basically identifying Western spies.”
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He added: “And that makes some sense because, of course, lots of people in Moscow are asking themselves the question why the US intelligence was so good.”
The Kremlin has publicly insisted the “special military operation” is going to plan despite reports it has ground to a halt.
CIA director Bill Burns told Congress recently the Russian leader had expected Ukraine to fall in two days.
Dmitry Peskov, Putin’s spokesman, told CNN on Tuesday claims Russia had expected a quick and easy victory were false and the invasion was going to plan.
He told CNN’s Christiane Amanpour: “Russia’s special military operation is going on strictly in accordance with the plans and with purposes that were established beforehand.”
He insisted no one had expected the operation to last “a couple of days” despite reports from Russia’s own state media appearing to suggest Putin had planned for a swift victory.
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Mr Soldatov said Russia’s struggles lie in underestimating the opposition of all levels of Ukrainian society rather than flawed intelligence.
Putin has frequently voiced his contempt for the country and its president, Volodymyr Zelenskyy, who had been fighting on the front lines with Ukrainian troops.
On the eve of the invasion, the Russian leader accused him of being a drug addict and said Ukrainian national identity was a “fiction”.
Meanwhile, the Pentagon has assessed Russian forces are “struggling on many fronts”, including trouble refuelling and other logistical challenges.
US intelligence this week assessed that Russia’s “combat power”, which comprised of over 150,000 troops amassed before the invasion, had dipped below 90 percent of its original force for the first time as Moscow has suffered heavy losses at the hands of Ukrainian soldiers.