An awful clash is imminent along the villages and fields south of Kostiantynivka in eastern Ukraine’s Donetsk Oblast. An industrial town with a pre-war population of 67,000, Kostiantynivka is the last major settlement between the front line and Kramatorsk, a city of 147,000 buttressing the last line of Ukrainian defenses in Donetsk.
Capturing Donetsk is one of Russia’s top objectives in its 39-month wider war on Ukraine. Holding Donetsk is one of Ukraine’s top objectives. Both sides are surging forces into the area around Kostiantynivka. The fighting is escalating. Casualties are piling up. And the worst is yet to come.
“The occupiers are trying to advance toward Kostiantynivka,” the Ukrainian army’s 93rd Mechanized Brigade reported last week. In fact, they’ve been trying for weeks now. An assault by around 150 Russian motorcycle troops on the village of Yelyzavetivka in mid-April may have signaled the beginning of the Russian offensive.
The 93rd Mechanized Brigade is one of no fewer than a dozen Ukrainian brigades—each with thousands of troops, thousands of drones, and hundreds of armored vehicles and howitzers—that have deployed battalions around the town.

Some of the Ukrainian ground forces’ best units are in the area. Not just the battle-hardened 93rd Mechanized Brigade, but also the aggressive 5th Assault Brigade and the 5th Heavy Mechanized Brigade, a reorganized tank brigade with up-armored Leopard 1A5 tanks.
They’re arrayed along a 30-kilometer arc—one end anchored to the southwest in the direction of Pokrovsk, the middle running through the outskirts of Toretsk and the opposite end anchored outside Chasiv Yar, to the northeast. “In the north, Russian forces are attempting to break through from the direction of Chasiv Yar,” the 93rd Mechanized Brigade noted, “while in the south they are attacking from the Pokrovsk highway.”
Ukrainian forces and earthworks are thinnest to the southwest. Probing for gaps in the line last week, the Russians advanced swiftly in this area, carving out a 15-kilometer-deep salient beginning around Yelyzavetivka and pointing toward Kostiantynivka, another 15 kilometers to the northeast.
Kostiantynivka is now within shooting distance of Russia’s short-range attack drones and smaller artillery pieces.

Russians frustrated after failure to capture Chasiv Yar
Frustrated by their failure to fully capture Chasiv Yar and Pokrovsk despite a year of costly effort, the Russians sense an opportunity in Kostiantynivka—and aren’t about to waste it for a want of resources.
A huge Russian force is gathering south of the town. No fewer than three Russian field armies—the 8th, 41st, and 51st Combined Arms Armies—are nearby. The 8th CAA is apparently taking the lead.

Russia’s asbestos tank armor didn’t work. Ukraine’s drones did.
There are more than 600,000 Russian troops in Ukraine; it’s possible one out of 10 is marching on Kostiantynivka. They’re paying in blood for every yard they gain. That initial Russian motorcycle assault on Yelyzavetivka was typical. Almost all the Russians involved in that assault were killed or wounded, but more Russians followed behind them.
Kostiantynivka is not lost. Yes, the Russians are extending a salient toward Kostiantynivka from the southwest. But the salient “is only one of the three necessary areas where Russian forces must make further advances in order to seriously threaten Kostiantynivka,” observed the Institute for the Study of War in Washington, D.C.
The other two areas are Chasiv Yar and Toretsk. And “Russian forces have struggled to break out” of those settlements, ISW noted. That “has likely complicated Russia’s plans for an offensive against Kostiantynivka and the wider Ukrainian fortress belt” running through Kramatorsk, according to the think tank.
Moreover, Ukrainian forces aren’t exactly standing still in the sector. On Sunday or Monday, Ukrainian troops counterattacked the Russian salient and, according to the Ukrainian Center for Defense Strategies, “pushed the enemy back slightly from the village of Zoria.”