A lightning-fast Ukrainian counteroffensive with the potential to be a turning point in Kiev’s fight against the Russian invasion has once again highlighted Moscow’s intelligence shortcomings in the war, analysts say.

The offensive has resulted in Ukraine recapturing the strategic city of Izyum – which President Volodymyr Zelenskyy symbolically visited on Wednesday – and driving Russian forces out of most of the country’s eastern Kharkiv region.

The push came after the conflict, which has been going on for more than half a year, seemed to have reached a kind of stalemate over the summer when Russian troops held large parts of eastern and southern Ukraine but did not advance much further.

“This is a colossal failure of Russian military intelligence, the fact that they didn’t see this buildup coming,” said Michael Kofman, senior research scientist at the Center for Naval Analyzes’ Russia Studies program.

“Russian military intelligence completely screwed it up,” he added.

“Russia did not anticipate Ukraine’s advance,” said Pierre Grasser, a historian of international relations and a researcher at the Paris Sirice Institution.

Echoing other analysts, Grasser said Ukraine benefited by using a major deception tactic, launching a counterattack in the south before launching an even more massive one in the northeast.

“However, weak signals could have alerted Moscow,” he said.

Ukraine has been active on the Northeastern Front since August through minor operations, while the conflict has also been marked by an unprecedented wealth of open-source information such as satellite imagery.

But the intelligence failure is also reminiscent of Russia’s apparent overconfidence six months ago in the expectation that its forces would rapidly advance through Ukraine and even capture the capital, Kyiv.

In the short term, Moscow appeared to scale back its priorities, focusing on taking control of the East and South rather than explicitly vowing regime change as its goal.

But faced with military setbacks and problems with reinforcements, President Vladimir Putin has so far refused to take any steps towards compulsory military service.

Rob Lee, a researcher at the Philadelphia-based Foreign Policy Research Institute (FPRI), said some Russian Telegram channels had been brewing a Ukrainian concentration around Kharkiv for a month.

“One of the greatest weaknesses of the Russian military is that it is slow to respond to changes on the battlefield,” he said.

Lee said that Russia in particular has been “caught on the wrong foot” by advances in Ukraine’s military equipment due to Western support, particularly the US-supplied HIMARS multiple rocket launchers.

“There are various explanations as to why these mistakes are being made, but they point to a very fundamental problem with Russian military leadership. Russian military decision-making is still very centralized,” he said.

Ukraine’s counter-offensive has also sparked open concern in Russia, with some pundits on state television dropping the line that what Moscow calls a “military special operation” went well.

The powerful leader of Russia’s Chechnya region, Ramzan Kadyrov, whose own militia fighters were involved in the invasion, spoke openly on his Telegram channel about the “faults” in Russian tactics.

He has now called on the head of each Russian region to gather 1,000 volunteers to fight in Ukraine.

Speaking in Moscow, Russian military expert Alexander Khramchikhin said Russia’s response was also complicated by Ukraine’s tactic of launching simultaneous attacks.

“The Russian secret service did not understand exactly where the actual counter-offensive would take place,” he told the AFP news agency.

Khramchikhin also said there is a big difference in mobilization between Russia and Ukraine.

“In Ukraine, the entire population is being mobilized,” he said. “This way, the Ukrainians can use as many workers as they want.”

In addition to arms shipments from the West, Ukraine has also benefited enormously from Western intelligence resources, he added.

“Ukraine receives real-time information from US satellites and long-range radar detection aircraft,” he said.