A bold Ukrainian advance into Russia’s Kursk region has seen Kiev forces seize several villages, capture hundreds of soldiers and force the evacuation of tens of thousands of civilians in what has effectively become the biggest attack in the country since World War II, the Associated Press comments.

After more than a week of fighting, Russian troops are still struggling to drive out the invaders.

Why was the Russian military caught so off guard?

Extended borders, with defenders elsewhere

The Russian regions of Kursk, Bryansk and Belgorod share a 1,160 km border with Ukraine, with 245 km being Kursk alone. This border had only token protection before Moscow’s invasion of Ukraine in 2022. It has since been strengthened with checkpoints on major roads and field fortifications in places, but building major fortifications has remained a very difficult task.

The most capable Russian units fighting in eastern Ukraine, where they launch attacks in several areas, with gradual but steady gains. Moscow has used the areas to launch airstrikes and missile strikes on Ukrainian soil, but it does not have enough ground forces there.

Due to the porous border and lack of manpower, there have been previous raids on Belgorod and Bryansk by pro-Kiev commando groups who fought alongside Ukrainian forces before withdrawing.

Russia’s drones, surveillance equipment and intelligence are focused on eastern Ukraine, which has helped Kiev to stealthily withdraw its forces to the border under the cover of forests.

Retired general Andrei Gurulev, a member of the lower house of the Russian parliament, criticized the army for its failure to protect the border.

“Unfortunately, the group of forces protecting the borders did not have their own intelligence,” he said characteristically on social networks. “No one likes to see the truth in reports, everyone just wants to hear that everything is fine.”

The element of surprise

Ukrainian troops participating in the invasion were reportedly briefed on their mission just a day before its start. That secrecy contrasts with last year’s counteroffensive, when Kiev openly stated its main goal was to cut off the land corridor to Crimea, which President Vladimir Putin illegally annexed in 2014. Ukrainian military action failed, as Ukrainian troops they crossed Russian minefields and were hit by artillery and drones.

Ukrainian troops did not cope corresponding obstacles during their invasion of the Kursk region.

Experienced mechanized units easily dealt with lightly armed Russian border guards and small infantry units composed of inexperienced conscripts.

Hundreds of Russians were captured, Ukrainian officials said. The Ukrainians advanced deep into the region in various directions, meeting little resistance and sowing chaos and panic.

“So far, the Russians appear in tactical and operational shock, which led to a slow tactical response and allowed the Ukrainians to continue to exploit their advance on Russian defensive lines,” retired Australian general Mick Ryan said in an analysis.

Russia responds, but slowly

The Russian military command initially relied on fighter jets and helicopters to try to stop the attack. At least one Russian helicopter was shot down and another damaged.

At the same time, Moscow began bringing in reinforcements, which succeeded in slowing the Ukrainian advance, but failed to block completely Ukraine’s maneuvers through vast forests.

“Russia seems to be doing very poorly when it comes to responding forcefully in a situation like this,” said military analyst Michael Coffman. “Russian forces do much better when they operate with a prepared defense, fixed lines, more of a war of positions.”

Kofman noted that the Russian reserves that arrived in the Kursk area seemed inexperienced in combat and had trouble coordinating with each other.

The danger for Ukraine

Kiev remains silent on whether it intends to seek to hold any position in the Kursk region or withdraw to Ukrainian soil. The first option is dangerous, because supply lines that run deep into the region would be vulnerable to Russian strikes, analysts say.

“The main risk is that the Ukrainians choose to entrench themselves in the region and hold ground, which lengthens the front line,” said Matthew Saville, director of military science at the Royal United Services Institute in London.

Ryan, a retired Australian general, warned that “the loss large number of forces in this scenario it also makes it a strategic and political liability.”

However, the invasion has already boosted the morale of Ukrainian public opinion, and has demonstrated the ability of Ukrainians to take the initiative to take the war to Russian soil.

“This Ukrainian operation represents a very important effort on the part of the Ukrainians to restarting the status quo to the war to change the narrative about Ukraine’s prospects in it,” Ryan noted.