The headlines make it sound like Russia is sweeping through eastern Ukraine, but the real story is much dirtier, slower, and deadlier. Right now, Moscow is grinding its teeth against what military strategists call Ukraine's fortress belt. This isn't just a random line in the mud. It's a 50-kilometer spine of heavily fortified, industrialized cities in the Donbas region that has kept the Russian war machine at bay for years.
If you want to understand where the war stands, look at Kostiantynivka. It sits at the southern tip of this belt, which also includes Druzhkivka, Kramatorsk, and Sloviansk. Russian troops are currently trying to squeeze into Kostiantynivka, using small infantry groups to seep into the outskirts. Vladimir Putin claimed his forces are on the verge of capturing it. Ukrainian commanders call that wishful thinking, but nobody denies the pressure is brutal. Don't forget to check out our recent article on this related article.
What happens here dictates whether Ukraine can maintain a defensible front line in the east. Lose this belt, and the flat terrain further west offers almost nowhere left to hide.
The Grind Inside Kostiantynivka
Moscow is relying on its raw manpower advantage to force its way into the urban core. According to local Ukrainian commanders, around 250 Russian soldiers have managed to establish interspersed positions inside the city, moving past simple infiltration into active urban combat. They are pushing from both the west and the east, threatening to semi-encircle the remaining defenders. If you want more about the context of this, NPR offers an in-depth summary.
The human cost is staggering. Kostiantynivka used to hold 70,000 people. Today, about 2,000 residents remain, huddled in damaged homes without basic utilities. The tactical reality is ugly. Russian units recently managed to reach a zinc plant in the center of town. They also blasted a dam near Osykove, flooding the area and cutting off the main road north to Oleksiievo-Druzhkivka.
This brings Kyiv to a harsh bottleneck. Analysts from the open-source mapping group DeepState point out that the pincer movements are forcing a brutal choice. Ukraine must either pour massive reinforcements into the burning city or pull back to preserve its troops.
The Sky Belongs to the Drones
Supply lines keeping the fortress belt alive are completely exposed. The highway running north from Kostiantynivka is an open graveyard of burned-out military transport vehicles. Russian artillery, Lancet drones, and heavy guided aerial bombs track every movement.
Members of the National Police "Predator" rifle brigade patrol these transit routes, trying to string up anti-drone netting and clear remote-dropped mines. The skies are so saturated with quadcopters that evacuating wounded or dead soldiers in standard trucks is suicide. Everything has to happen on foot, under the canopy of trees, or in the pitch black of night.
To the north, the cities of Sloviansk and Kramatorsk are catching the overflow. Russian artillery positions are only about 15 kilometers away, allowing them to rain down unguided shells alongside massive 3,000-pound aerial bombs. In Sloviansk alone, the main hospital handles up to 15 civilians injured by drone strikes every single week.
The War in the Rear
You might wonder how Russia keeps this up when its own economy is cracking. Kyiv has launched relentless intermediate-range drone strikes hitting Russian fuel hubs, refineries, and supply lines running through occupied Crimea. It is working to some extent. Russian authorities in Crimea had to declare a state of emergency and halt fuel sales to private individuals and businesses due to severe shortages.
Yet, the frontline offensive keeps rolling. The Kremlin's strategy relies on decentralized, low-tech brutality. Russian frontline assaults frequently consist of just one or two soldiers sprinting from trench to trench. They take heavy losses in the rear, but Moscow simply replaces the dead.
Denis Pushilin, the Kremlin-installed head of the occupied Donetsk region, dismissed questions about how slow the Russian advance is going. To Moscow, time doesn't matter. Manpower doesn't matter. Only the ground does.
Why the Next Few Weeks are Crucial
This brings us to what needs to happen next for the defense of the Donbas. Ukraine cannot rely solely on localized drone victories to hold the line. The immediate priority requires engineering units to establish secondary fallback lines west of the H-20 highway while the urban fighting inside Kostiantynivka delays the Russian advance.
Logistics teams must also diversify their supply routes. Relying on single asphalt highways under constant drone surveillance is failing. Moving supplies via smaller, unpaved dirt networks through agricultural fields is slower, but it limits the effectiveness of Russian spotter drones. Western military aid, particularly electronic warfare jamming gear and short-range air defense systems, needs to be pushed directly to the brigade level in Druzhkivka and Kramatorsk immediately. Without tools to blind the Russian drones, holding the rest of the fortress belt through the summer will become an impossible task.
