From Amos C. Fox:

The July 11, 2014 strike at Zelenopillya is perhaps the most noticeable example to emerge from the war of the combined effects of tactical drones with the battalion tactical group—a task-organized force designed to achieve tactical overmatch against opponents—and its organic fires capabilities. The attack was a preemptive undertaking against Ukrainian brigades, postured in assembly areas, which were preparing to conduct offensive action against Russian and partisan forces. The buzzing of tactical drones and cyber-attacks targeting Ukrainian communications preceded the strike. An onslaught of rockets and artillery fell on the Ukrainian position shortly after the drones arrived, leaving thirty Ukrainian soldiers dead, hundreds more wounded, and over two battalions’ worth of combat vehicles destroyed. This strike created anxiety within the US Army, specifically in relation to the sophistication of Russian cyber capabilities and the effectiveness of the new Russian reconnaissance-strike model. This strike also highlights the disparity in artillery and rocket munitions between Russia and the US Army. Russia still possesses and employs a variety of munitions, to include dual-purpose improved conventional munitions and thermobaric munitions, that the US Army elected toeliminate from its arsenal…

A rapid, violent, decisive victory in which hundreds of Ukrainian soldiers are killed in a matter of days is counterproductive to Russia’s political goals, whereas the incremental use of violence over time accomplishes the same objectives with less disturbance to the international community…

Looking beyond Eastern Europe, Russia is employing a similar approach to war in Syria, specifically in Aleppo. Russian armed forces, in conjunction with Syrian allies, have encircled the city, cut all ingress and egress routes, and ruthlessly assaulted the city. So Russia’s fondness for the siege is evidently not unique to Ukraine. The methods Russian forces employ in Syria are different than those in Ukraine; for example, in Syria they use airpower in lieu of the rocket and artillery fire in Ukraine. But the approach—use of the siege to achieve political ends—is the same in both.