Russia learned the wrong lessons from previous wars

 From David Volodzko / Daily Beast, The Embarassing Truth Behind Putin's War Failures:

"Russia has been forced, humiliatingly, to withdraw some 40,000 troops from around Kyiv and Chernihiv, having failed to make any significant progress in those regions—falling back to their old targets in eastern Ukraine. This raises the question of exactly what the Kremlin learned in Syria and, more importantly, what it should have learned but obviously has not...

Some of the lessons that were not learned well enough include use of drones for artillery spotting, the danger of MANPADS on the contested battlefield, and the need for secure supply lines. Each of these factors has proven devastating for Russian forces in Ukraine...

Russia learned a few more things in Syria. Namely, how to destroy cities, terror tactics to make civilians flee, and the use of proxies as holding forces/cannon fodder.

So what went wrong? For one thing, Russia is one of the most corrupt nations in the world, and by far the most corrupt major power. Ruling a mafia state has its advantages if you’re the Godfather, but it’s hard to know whom to trust. Moscow recently purged 150 Federal Security Service (FSB) agents and sent Sergei Beseda, the head of the FSB’s 5th Service, which handles intelligence in Ukraine, to Lefortovo Prison, which was used under Stalin to conduct torture-based interrogations and mass executions. One theory says Beseda gave information to the CIA, but the official reason, which may very well be true, is that he lied to the state and stole funds meant for espionage activities in Ukraine. If true, this means Putin’s own spy chiefs not only let him bring a knife to a gun fight—they sold off the combat blade and bought a cheap butter spreader...

Russian communications are very lowbrow, and they are using unencrypted mobile phones in Ukraine, a bad habit picked up in Syria, where few opponents could understand Russian or had the technical competence to intercept...

One thing’s for certain, Russia looked at Ukraine and mistook a tiger for a cat. Now even if it decides to cut its losses and completely withdraw, it may not be so easy. As the old Chinese saying goes, when you’re riding a tiger, the hard part is getting off."