Just weeks into its war in Ukraine, Russia has shifted its focus to the country’s east, redeploying weapons and troops and increasing attacks on key towns and cities.
Moscow said Tuesday that it had started the “next phase” of the invasion in the eastern part of Ukraine. Russia plans to seek “the complete liberation of the Donetsk and Luhansk republics,” Russian Foreign Ministry Sergei Lavrov said in an interview, referring to the two territories where pro-Moscow separatists have fought Ukrainian forces for years.
Ukrainian President Volodymyr Zelensky also said in an address late Monday that the “battle for Donbas” had begun.
Russia’s pivot to friendlier territory in the east comes after its forces failed to capture the Ukrainian capital, Kyiv.
At the start of the invasion, the Kremlin appeared confident that the city would fall without a fight, cowed by the speed and strength of Russia’s advance.
“They’re going to do this in a fast-moving, Hollywood style,” Jim Townsend, the deputy assistant secretary of defense for Europe and NATO during the Obama administration, recalled thinking at the time.
But almost immediately, Russian forces stalled outside the city, hobbled by poor planning and critical supply shortages.
They also lacked the sheer manpower to occupy Kyiv, a metropolis of nearly 3 million people.
Its surface area — more than 300 square miles — is more than twice that of Washington D.C.’s. “There’s just a lot of terrain [Russia] would need to cover, and Russian combat forces are actually somewhat light on infantry,” said Scott Boston, a senior defense analyst at the Rand Corp.
Kyiv is bisected by the Dnieper River, “like two large cities that can mutually support one another across the river,” Boston said. Ukrainians seized on that geography, destroying bridges near the city. Flooded areas also may have impeded a Russian advance.
Russian forces also failed to quickly capture Antonov Airport, which would have allowed them to establish a base to bring in more equipment and supplies. They eventually captured the area, but by then, they were bogged down with intense battles.
Russia’s delay allowed Kyiv to build up its defenses and prepare for an urban battle — one that Moscow wasn’t prepared to fight.
BEFORE THE INVASION
As the conflict began, Kyiv was not ready, but the city environment meant Ukrainians had an edge.
Urban areas are a three-dimensional terrain in which attackers must consider a 360-degree sphere of potential threat. Defenders have an advantage, but they must worry about limiting harm to civilians and the city itself.
Buildings provide high angles from which to shoot as well as cover from observation and attacks. Robust concrete structures, such as banks or government buildings, may be used as a strongpoint from which to defend.
Underground spaces, such as maintenance tunnels and subways, offer areas to depot supplies, protect from aerial attacks and conceal movement from the enemy.
AFTER THE FIRST SHOTS
Within days of Russia’s initial attacks, the streets of Kyiv transformed.
Caches of supplies and weapons, such as armored personnel carriers and antitank rockets, were placed throughout the city, and antiaircraft guns were deployed around buildings.
Barricades and checkpoints formed around the city. Trucks, buses, large concrete blocks, tires and sandbags formed barriers to protect Ukrainian defenders and block the advance of enemy troops and armor down city streets.
Barricades also redirect the enemy to areas that defenders have pre-targeted with artillery and explosives.
The time the capital had to prepare made Kyiv even harder for Russia to seize.
“A prepared defense is the worst-case scenario for an attacker,” Boston said.
CHALLENGES OF URBAN WARFARE
In late March, Russia appeared to change its strategy, shifting resources from around the city to the eastern part of the country. Occupying Kyiv would have meant urban warfare, a scenario experts say favored Ukrainian fighters.
To take a city by force, an attacking army may often use infantry and armor. Each support the other in what is known as combined arms operations as they advance street by street.
Staying in buildings can limit an adversary’s use of aerial surveillance, though unmanned aerial vehicles (UAVs) can dissuade defenders from congregating openly on rooftops.
Defenders take advantage of their reinforced positions to degrade the enemy. Short-range antitank weapons such as NLAWs and RPGs could be used to eliminate tanks which infantry use for cover.
Without protection from armor, attacking troops are more vulnerable to small-arms fire from behind barricades and windows above.
Defenders may also make openings in interior walls, called mouse holes, that allow them to attack from one spot and then quickly move to another location in the building. Holes in exterior walls may be made by an assault force to surprise an enemy inside a building.
The urban terrain favors those who are defending. An attacking force needs to commit a large number of troops and resources to not only take a city street-by-street, but also hold those areas.
Once it became clear that this was a losing battle for Russia, the shift toward the east began in earnest.
“They decided [to withdraw] because they had no other decision to make,“ said Jeffrey Edmonds, the former director for Russia on the National Security Council.
“It wasn’t like, ‘Well, we can take the city, but it’s going to cost us too much,’ " said Edmonds, who also served with the U.S. Army in Iraq. “They just couldn’t do it.
Russia began pulling its troops from Kyiv in late March, sending some north to Belarus and others to the Donbas region in eastern Ukraine. The energy-rich region on Russia’s western border is held in part by allied separatists, offering Moscow safer territory from which to launch attacks and resupply its forces.
The open terrain is better for Russian armored units, experts say. Near Kyiv, they were forced to use roads, putting forces on a predictable route vulnerable to ambushes and attacks from the air.
Satellite images taken by Maxar Technologies have in recent days shown multiple convoys of Russian vehicles, weapons, troops and equipment moving in and around Ukraine’s east. Experts say Russia may try to besiege Ukrainian forces by linking its troops in the north and the south. It is an effort that analysts warn could include the blockade or capture of more eastern cities.
Local officials have told The Washington Post that Russia was attempting a “scorched earth” tactic to gain full control of Donetsk and Luhansk, two regions that make up the broader region of Donbas.
To achieve that, analysts say, Russia is likely to try to encircle Ukrainian troops in the east by connecting their troops in the north with their troops in the south.
To do so, they would probably need to capture or surround key eastern cities such as Izyum. Local officials announced last week that Izyum, a city of roughly 40,000, was taken by Russian forces after three weeks of artillery fire and airstrikes.
If Sloviansk, a city of more than 100,000, were to fall, it could allow Russia to encircle Ukrainian troops in the east, cutting them off from supply lines.
Other nearby cities, such as Kramatorsk to the south or Severodonetsk to the east, could also become surrounded by Russian troops.
Russia has already used siege tactics in Ukraine, surrounding and bombarding the port city of Mariupol, as well as Chernihiv in the north. Encircling, isolating and then pummeling a city requires less manpower and equipment than an urban war for control of a major capital.
So far, no large eastern city has surrendered to Russian forces — but their defense has come at an enormous cost. The mayor of Mariupol said this week that Russia’s siege may have killed more than 20,000 civilians, a figure The Post could not independently verify.
The devastation itself can make it hard for the aggressor to hold a city, alienating the local population and breeding further resistance.
“The encirclement and siege of key towns and cities is very destructive and imposes huge costs on the local population,” said Tracey German, a professor in conflict and security at King’s College London.
“Even if Russia achieves a military victory — which is not a given — it is not clear how it can achieve a longer-term political victory after its destructive and indiscriminate use of force,” she said.