No development during Vladimir Putin’s 23 years in power has so clearly pointed to his regime’s fragility as the Wagner Group’s aborted mutiny late last month.

The Wagner mercenaries, led by Yevgeny Prigozhin, brazenly challenged the Kremlin’s authority — and now appear to have gotten away with it. Russia’s internal security service, the FSB, has abandoned its criminal investigation into the revolt. But Putin’s problems hardly end with Wagner.

Prigozhin’s fighters would not have been able to travel almost 1,000 kilometers (621 miles) within Russian territory in less than a day without help from members of Putin’s inner circle or the military. Rumors are swirling that the billionaire brothers Yuri and Mikhail Kovalchuk may have played a role. The Kovalchuks, close associates of Putin, reportedly share Prigozhin’s belief that Russia has not been forceful enough in the war or in its broader confrontation with the West.