An aborted armed mutiny by Wagner mercenaries exposed Russia’s porous home front, shook Russian President Vladimir Putin’s authority and resulted in the removal of thousands of seasoned fighters from the battlefields of Ukraine.

Remedying the fallout will be costly, especially with elections looming next March in an economy worn down by almost 17 months of war and sanctions.

And in a reminder of the threats Russia now faces, authorities on Monday said two Ukrainian drones caused explosions that killed two people and damaged the symbolic bridge to Crimea, the peninsula Putin annexed from Ukraine in 2014.