Why Ukraine’s swift push into Kursk shocked Russia

A daring Ukrainian military push into Russia’s Kursk region has seen Kyiv’s forces seize scores of villages, take hundreds of prisoners and force the evacuation of tens of thousands of civilians in what has become the largest attack on the country since World War II.

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

Why the Russian military seems to have been caught so unprepared:

Russia’s regions of Kursk, Bryansk and Belgorod share a 1,160-kilometer (720-mile) border with Ukraine. That includes a 245-kilometer (152-mile) section in the Kursk region. This frontier had only symbolic protection before Moscow invaded Ukraine in 2022. It’s been reinforced since then with checkpoints on key roads and field fortifications in places, but building solid defenses has remained a daunting task.

The most capable Russian units are fighting in eastern Ukraine, where they have been pressing offensives in several sectors, with incremental but steady gains. Moscow has used the regions to launch airstrikes and missile attacks on Ukrainian territory but doesn’t have enough land forces there.

Because of the porous border and manpower shortages, there have been earlier forays into the Belgorod and Bryansk by shadowy groups of pro-Kyiv commandos fighting alongside Ukrainian forces before they pulled back.

Russia’s drones, surveillance equipment and intelligence assets are focused in eastern Ukraine, helping Kyiv to covertly pull its troops to the border under the cover of deep forests.

Retired Gen. Andrei Gurulev, a member of the lower house of Russia’s parliament, criticized the military for failing to protect the border.

“Regrettably, the group of forces protecting the border didn’t have its own intelligence assets,” he said on a channel of his messaging app. “No one likes to see the truth in reports, everybody just wants to hear that all is good.”

Ukrainian troops participating in the incursion reportedly were told their mission only a day before it began. That secrecy contrasted sharply with last year’s counteroffensive, when Kyiv openly declared its main goal of cutting the land corridor to Crimea, which President Vladimir Putin