Here’s the central dilemma of the Ukraine invasion: This is a war Russian dictator Vladimir Putin believes he “cannot afford to lose” (in the words of U.S. Director of National Intelligence Avril Haines), but it’s also one he cannot seem to win. It took U.S. troops only three weeks to take Baghdad in 2003. But the Ukraine war is now almost three weeks old, and Putin is as far as ever from his stated objectives of “demilitarization and denazification,” meaning the imposition of a Russian puppet regime in Ukraine.

His best bet was a blitzkrieg toward Kyiv in the war’s early days. But that fizzled out, and the Russian army hasn’t shown the ability to consistently supply its armored columns or coordinate air and ground operations. The Russians have made better progress in the south than the north, but their advance is now stalled, and they still can’t dominate the skies. The Ukrainians have mounted a skillful and dogged defense — a military task that is inherently easier than conducting an offensive.

The Russian army is trying to make up for its lack of military skill with sheer brutality. It is pounding Mariupol and Kharkiv into rubble, deliberately targeting civilians just as it once did in Aleppo, Syria, and the Chechen capital of Grozny. Kyiv’s turn is likely next. Putin might even use chemical weapons. But such brutality can often boomerang by leading to stiffer resistance.

Note that Russia’s ally Bashar al-Assad still hasn’t snuffed out Syria’s rebellion nearly seven years after Russia’s intervention despite (or because of) all the regime’s atrocities. Or consider how Leningrad withstood a German siege of nearly 900 days from 1941 to 1944. That’s a story Putin should know well since Leningrad, now called St. Petersburg, is his hometown, and his brother died in the siege. The population starved but did not surrender.

Demolishing a city with artillery and rockets is easy; occupying it is much harder. Rubble creates fighting positions for defenders and impedes movement by armored vehicles. It took Iraqi forces, supported by the U.S. military, nine months from 2016 to 2017 to retake Mosul from only about 6,000 Islamic State fighters. Is Putin willing to wait for a lengthy siege of Kyiv while sanctions continue to hammer the Russian economy and the body bags keep coming home?