The cross-border raid shows that Russia’s security, once bolstered by a formidable military machine, has declined markedly since last year’s invasion, said Sergey Radchenko, an international relations expert at Johns Hopkins University.

“That is why Ukrainian intelligence bothers with operations that actually have no other meaning, to show the weakness of the Russian state. That is the message that is being sent,” he told NBC News.

«The results of Putin’s disastrous invasion speak for themselves: Russia is much less secure and much less capable,» Radchenko added.

He said the drone attack on the Kremlin on May 3, which Moscow immediately dismissed as a Ukrainian assassination attempt on Putin, a charge denied by Kiev. — similarly showed state vulnerabilities.

In an apparent effort to show the force of their response, a video shared widely on Russian social media and geotagged by NBC News showed a high-ranking general leading the operation to repulse the incursion earlier this week, directing the troops in military uniform and urging them to advance along a road in a residential area near the border.

Defense Minister Sergei Shoigu told a news conference on Wednesday that the pro-Ukrainian fighters were «returned to the territory of Ukraine, where they continued to be defeated until they were completely eliminated.» He vowed to «react promptly and extremely harshly» to future cross-border raids.

But the Kremlin’s response was ridiculed by Ukraine’s supporters and appalled by its own influential pro-military figures.

In a sign that Russia’s recent claim to a token battlefield prize had done little to ease internal dissent, the mercenary chief who led that campaign in Bakhmut also issued a warning.

Yevgeny Prigozhin, the founder of the Wagner mercenary group, expressed fears on Wednesday that Russia could not only lose the war but also face a 1917-like revolution unless the country’s ruling elite intensifies its approach. «We need to impose martial law,» said Prigozhin, who has been an outspoken critic of Moscow’s military leadership.