In a war that’s continually confounded expectations and brought us to the brink of World War III more than once, you’d think by now we would have lost the ability to be surprised by developments in Ukraine. And yet, life finds a way, as this past weekend saw the most serious challenge to Russian president Vladimir Putin’s rule and the stability of the Russian state more generally in his nearly two decades in power.

Last Friday, mercenary leader Yevgeny Prigozhin launched what was, depending on who you ask, either a mutiny, a coup attempt, or a protest against the Russian government, after months of bubbling resentment at what he viewed as his soldiers’ mistreatment at the hands of an incompetent military leadership. Some commentators have expressed suspicion that Prigozhin’s real motivation was the Kremlin’s June announcement that his private military company, the Wagner Group, would be coming directly under the control of the Russian Ministry of Defense, leading Prigozhin to make a play to try and secure his moneymaker.

Whatever the exact truth, the result was alarming scenes of Wagner troops and tanks rolling unopposed into Russian cities, seizing military headquarters, shooting down Russian military helicopters, and announcing that they were making a beeline toward Moscow, with Prigozhin calling for the removal of Russia’s top military leaders. Though short-lived in the end, the Kremlin clearly took the threat seriously, barricading roads into the capital, mobilizing Chechen leader Ramzan Kadyrov’s troops to meet the rebellion, and putting out videotaped statements from military and other officials calling on Prigozhin to stop what he was doing and for Wagner troops not to follow.