(dramatic music) - [Narrator] This video shows a group of Russian soldiers surrendering to Ukrainian troops outside the Russian border town of Suja. (driver speaking in foreign language) - [Narrator] The surrender came during Kiev's biggest attack on Russian soil to date. - The Ukrainian forces have managed to push at least a dozen miles into Russia in just a few days, which has been a huge shock for Russia and for the West. (speaking in foreign language) - [Narrator] In the first few days after the incursion, many details were unclear. The Journal verified social media footage, analyzed satellite images, and spoke to land warfare experts to understand how Ukraine managed to pull off one of its most ambitious operations in this war. - So this is a full-fledged, mechanized incursion into Russia, the first since 1941. - [Narrator] The offensive took place

in the border region of Kursk, which sits on a stretch of some 300 miles of the Ukraine-Russian border, relatively unscathed by the war. While Russia did launch its 2022 invasion from this part of the country, they were then pushed back. It hasn't become a frontline like the frontline within Ukraine. [Narrator] But the status quo in this area of the border was broken in May 2024 when Russian forces crossed into Ukraine from the Belgorod Region, targeting the country's second-largest City of Kharkiv. Over the following months, President Volodymyr Zelensky and other Ukrainian officials publicly expressed fears of a similar Russian attack on Ukraine's northern region of Sumy. Some military experts The Journal spoke with said these reports have been coming mainly from Ukrainian sources and suggested this could have been a tactic by Kyiv to allow it to build up its own forces in the region.

without too much scrutiny. And there have been other more obvious preparation tactics. - The one thing that the Ukrainians have done very successfully ahead of this assault was to strike Russian infrastructure in the Kursk Region. Clearly, they were preparing the ground so that when they launched this attack, it was able to move faster and have a bigger impact, and to impede Russia's response. - [Narrator] In early August, hundreds of Ukrainian troops crossed into Russia. (speaking in foreign language) - It's completely unprecedented. Ukrainian commanders have gone over the border before during the war, and they've staged raids, and then withdrawn after a few days, and these units tended to be lightly armed. They came in, they caused a bit of trouble, and they left. What's different this time is that Ukraine has sent much more serious forces in, so we've seen tanks moving in, we've seen armored vehicles, drones, air defense missiles,

serious artillery being used. (artillery blasting) - [Narrator] It also came as a surprise that Ukraine, which is struggling with a lack of manpower, would want to open a new front. - The main fighting is in Northeast Ukraine, East Ukraine, Southeastern Ukraine. No one was expecting for the Ukrainians to actually attack mainland Russia, least of all the Russians. - [Narrator] A week into the incursion, the Ukrainian military claimed it controlled 386 square miles of Russian territory, and more than 80 settlements. This sparked a massive evacuation in Russia, and an angry response from President Vladimir Putin. (speaking in foreign language) - Ukrainian troops are on fast-moving armored vehicles so they can move quickly and exploit opportunities. What they've done is now they've gained a foothold to strike Russian reinforcements as they come in before they can hit the battlefield. - [Narrator] This video corroborated by The Journal,

shows a Russian military convoy some 20 miles from the border with Ukraine, apparently smashed by a Ukrainian strike. A military analyst with the International Institute for Strategic Studies, a think tank, said, Russia has been overconfident, leaving its border exposed with poor defenses. Satellite images show fortifications such as rows of concrete pyramids designed to obstruct tanks and trenches, but Russia appears to have had weak forces in position. By analyzing road signs, foliage, and satellite images, The Journal was able to geolocate this clip to an area close to a border crossing near Suja. The video shows a group of men in military uniform surrendering with a white flag. - Ukrainian units we spoken with told us that it was mostly conscripts who were based there. They were quickly overrun by Ukrainian forces. - [Narrator] Despite the apparent successes, questions remain over how much this operation will cost Ukraine,

and what it was attempting to achieve. Military analysts say, Kyiv is seeking to divert Moscow's resources away from other parts of the front line, where Ukrainian forces are under intense pressure. (canon blasting) - The problem is that Ukrainian forces are already threadbare on the Eastern front. By sending in more Ukrainian troops, they're taking a risk by thinning out those forces in the East even more and allowing Russia potentially to take advantage. If Russia is able to strike back and bring its size and strength to bear in the Kursk region, Ukrainians will start to ask, Was it worth risking all of these troops and all of this equipment on this incursion? - [Narrator] Several experts The Journal spoke with suggested that Kyiv might be pursuing non-battlefield goals. - There's a bigger point here, which is about narratives. We're coming up to the US presidential elections in November,

Ukraine wants to give a message to whoever is going to be the next President of the United States. Ukraine can win, and that it is worth sending billions of dollars more in military aid to back up Ukraine because it's not out of this fight yet. (laughs) (speaking in foreign language) (laughs) (dramatic music)

How Ukraine Pulled off a Surprise Invasion of Russia | WSJ

The Wall Street Journal takes you inside carefully selected stories and events in a visually captivating way so you can dig deeper into the news and insights that matter to you. 

How Ukraine Pulled off a Surprise Invasion of Russia | WSJ

How Ukraine Pulled off a Surprise Invasion of Russia | WSJ

Scripts