Russia's army has learned to plug its frontline defenses in Ukraine with convicts, marines, and special-ops troops

• Russia's military spent months fortifying its positions ahead of recent Ukraine's counteroffensive.
• Its strategy involves using convicts, conscripts, regular troops, and Spetsnaz in different roles.
• Russia "varied force quality," and its strategy shows how it's dealing with that, one expert said.

The Russian Army has been mocked and reviled for its indifference toward the lives of its own soldiers in Ukraine, but it is now integrating its "disposable infantry" with elite troops in a cynical but so far effective strategy to hold the line against Ukraine's ongoing counteroffensive.