THE LAST time that Russian forces fought their way into Kyiv was the autumn of 1943, when the Red Army crossed the Dnieper river and seized the city from Nazi Germany. On November 4th that year, German defences collapsed and Soviet tanks poured into the Ukrainian capital. Almost 80 years on, Russian armoured forces are back.

As the third day of the current war in Ukraine drew to a close, Russia intensified pressure on three population centres: Kyiv, the capital; Kharkiv in the north-east; and Kherson in the south. In all of them, Ukrainian resistance was fierce. A large number of destroyed or abandoned Ukrainian vehicles were visible east of Kherson, though the city was said to be contested still on Saturday evening local time. There was also heavy fighting in Mykolaiv, further west, and just 110km from the key port of Odessa. Russian forces in the south also moved east towards Mariupol, a port city on the Sea of Azov that is claimed by the “People’s Republic of Donetsk”, one of a pair of Russian-backed statelets in the Donbas region of eastern Ukraine. In Kharkiv images and videos posted on social-media showed burnt-out Russian howitzers, with shells and cluster-munition casings lying in the street.

The most important battle was, again, for Kyiv. Russia failed to seize an airport on its outskirts on February 24th, the first day of the war. The next day saw fighting on the edges of the city, probably involving Russian paratroopers and special forces. Video footage taken on February 26th indicated fighting deeper into the city. Ukraine’s government also claims to have shot down two Russian transport planes, one of them near Vasylkiv, south-west of Kyiv, as well as several warplanes (this could not be independently confirmed).

Despite its impressive resistance, the city faced the prospect of imminent encirclement. Russian forces in Belarus are moving south, towards Kyiv, on several axes to the east and the west of the city. British defence intelligence said on February 26th that the bulk of those forces were now within 30km of Kyiv, having advanced 20km since the previous day. Residents of Kyiv dug trenches, prepared fortifications and built improvised tank traps. Ukrainian authorities continued to blow up bridges around the city to impede Russian incursions.

Yet even as it massed forces around Kyiv, Russia’s strategy to subjugate the city remained unclear. One option would be for Russian battalion tactical groups or BTGs—the fighting formations of Russia’s ground forces—to halt on the outskirts of the city, essentially mounting a siege until Volodymyr Zelensky, Ukraine’s president, surrendered and ordered his troops to lay down their arms. Yet Mr Zelensky’s defiant videos from the capital’s streets, and his refusal to heed American entreaties to fall back to the western city of Lviv, suggests that he will not give up easily.

For a siege to be effective it also has to block all entries and exits to a city, “otherwise you will see continued influx of weapons, supplies and reinforcements,” says Rita Konaev of Georgetown University. Russia learned that lesson during the first Chechen war, in the mid-1990s, she says: “We will be seeing a more extensive aerial and artillery bombardment campaign before anything else.”

Russia may ultimately be drawn into the city to seize crucial sites and overthrow the government directly. But Kyiv has the “perfect terrain to defend”, observes Anthony King of Warwick University, the author of “Urban Warfare in the Twenty-First Century”. It is large, dense, bisected by a river, criss-crossed with roads and rail lines and has an extensive metro and sewer system that could be used by defenders, says Mr King, who adds that the only consolation for Russia is the relatively flat terrain. “It could be a terrible strategic mistake by Vladimir Putin because he’s underestimated the urban problem.” Franz-Stefan Gady of the International Institute for Strategic Studies, a think-tank in London, points out that attackers in built-up areas are thought to require an advantage in manpower of six to one—a figure that originates in the Soviet experience during the second world war—far higher than that assumed for combat in open terrain. British doctrine demands ten to one.

The problem for Russia is that its BTGs tend to be heavy on artillery and light on infantry, according to a study published in 2017 by an American army officer in ARMOR, the official journal of the US Army’s armoured forces. That lopsided structure can compel Russian commanders to turn to light-infantry militias. But when Russia tried that in eastern Ukraine in 2014-15, arming and aiding pro-Russian separatists, they struggled to defeat Ukrainian defenders in critical battles, including one for Mariupol. Russian commanders in that conflict often opted for “prolonged sieges”, with heavy use of artillery and rocket fire, instead of ground assaults. The Russian invasion force includes “siege artillery", such as heavy mortars and artillery pieces, and Uragan and Smerch rocket launchers.

Even Western armed forces with air superiority, large stocks of precision-guided munitions and greater sensitivity to civilian casualties have inflicted enormous damage to cities. In 2004 fighting between American forces and insurgents in Fallujah, in Iraq, damaged or destroyed 70% of the city’s buildings. When a coalition including Iraq, America and others liberated Mosul, another Iraqi city, from the Islamic State group in 2016-17, over 10,000 civilians were killed—around 3,200 of them by the coalition—and two-fifths of the civilian population had to flee. It was also lethal for those on the ground: Iraq’s army suffered 10,000 casualties.

All of this bodes ill for Kyiv and its inhabitants. On February 25th Mr Putin seemed to offer a pretext for attack, ominously accusing Ukrainian “neo-Nazis” of placing heavy weapons in the centre of Kyiv and Kharkiv, “acting in the same way that terrorists act all over the world—using people as shields”. The scale of fighting in Kyiv could compare to Grozny, warns Mr King, referring to the terrible damage that befell the Chechen capital—a far smaller city than Kyiv—during two wars with Russia.

In the first of those battles, he notes, Chechen forces cleverly let Russians enter the city and travel to its centre—after which they unleashed mobile “hunter-killer” squads on the intruders. The first Russian armoured column that entered Grozny on New Year’s eve in 1994 lost 105 of its 120 tanks. Russian deaths probably numbered in the thousands. When the city was besieged and assaulted again several years later, in a war overseen by Mr Putin, Russian casualties were lower but several thousand civilians were killed.

So far, Russia’s defence ministry has not reported a single casualty in Ukraine; the Ukrainians claim there have been large numbers. The pretence of a bloodless war is already becoming impossible to sustain. There have been numerous anti-war protests in Russia, especially in Moscow and St Petersburg, though the authorities are cracking down hard. Should the army have to battle its way bloodily though Kyiv, that would be plain for Russians, and the world, to see. ■

Our recent coverage of the Ukraine crisis can be found here