Russia's expulsion of Ukrainian forces from Kursk removes hurdle to peace

By Guy Faulconbridge

MOSCOW (Reuters) -Russia's ejection of Ukrainian troops from the Kursk region ends the biggest incursion into Russian territory since World War Two, removing another barrier to a peace deal Moscow was reluctant to conclude with so many enemy troops on its soil.

The day after Moscow announced the completion of the Kursk operation, President Vladimir Putin declared a unilateral three-day ceasefire to mark the 80th anniversary of the victory of the Soviet Union and its allies in World War Two. 

Two Russian sources told Reuters on condition of anonymity that settling the war while Ukrainian troops were in Kursk was not acceptable to the Kremlin. 

Just over two years after Russia's 2022 invasion, Ukraine on Aug. 6 launched its boldest attack, smashing through the Russian border into the Kursk region, supported by swarms of drones and heavy Western weaponry.

At its height, Ukrainian forces claimed nearly 1,400 square kilometres of Kursk, but the attack proved costly for Kyiv. 

Russia has since taken around 2,000 square kilometres in Ukraine and now controls a chunk of the country nearly equal to the size of the U.S. state of Pennsylvania, according to Ukrainian open source maps. 

Some analysts say Russia's accelerated advance, mainly in eastern Ukraine, was aided by the diversion of Kyiv's forces to Kursk. 

"Essentially, Ukraine traded territory it values the most -its own - for territory it didn't value and that it couldn't hold forever," said Christopher McCallion, a fellow at Defense Priorities, a Washington DC think tank advocating for a strong U.S. military with a restrained foreign policy.

Ukraine, which has been retreating for weeks but still claims to have some active forces in Kursk, maintains the incursion distracted Russia from making even more gains on parts of the eastern front by forcing Russia to commit troops elsewhere. Kyiv has said its goals also included protecting its Sumy border region and gaining a territory that could be swapped in future peace talks. 

Those talks, driven by Washington's shuttle diplomacy, are now underway, without Ukraine's hoped-for bargaining chip.

Huge differences remain that could scupper U.S. President Donald Trump's peace effort, however. If the talks flounder, Russian forces will simply fight on, one of the sources said.

The Kremlin did not immediately respond to a request for comment. In response to a request for comment, Ukraine's military general staff denied hostilities had ended in the Kursk region and said Ukraine's defensive operation there continued. 

In recent weeks, Russia has stepped up attacks in Sumy, across the border from Kursk, local officials have said. On April 14, a Russian missile attack killed 35 people in Sumy's capital city. Russia said it had targeted a gathering of Ukrainian soldiers.

Despite doubts in Ukraine about whether the Kursk offensive was worth it, President Volodymyr Zelenskiy has acknowledged that Kyiv's forces were now active in Russia's Belgorod region, also on the border, describing it as an effort to protect towns on the Ukrainian side.

Russia occupies slivers of land across the border from Belgorod in Kharkiv. Under U.S. proposals, Ukraine could regain full control of its territory in Kharkiv as part of a peace deal while Russia would retain control over just under a fifth of Ukraine. 

THE BATTLE FOR KURSK

For the Kremlin, the incursion into Kursk, scene of the largest ever tank battle in history between Soviet forces and Nazi Germany in 1943, was an embarrassment.

The announcement of victory over Ukrainian troops comes ahead of 80th anniversary of the Soviet Union's victory over the Nazis on May 9. It gives Putin a win to showcase in front of invited dignitaries, including China's Xi Jinping and Brazil's Luiz Inacio Lula da Silva.

Despite prior warnings that an attack could come, Russian forces were surprised by the Ukrainian assault, according to Russian sources.

Russian officials at the time spoke of chaos as Russian civilians fled east and Russian border guards and army tried to battle small, highly mobile Ukrainian units speeding along the country roads of Kursk with Western weaponry and vehicles. 

At least 120,000 people were evacuated and a visibly irritated Putin was shown publicly scolding the then governor of Kursk, Alexei Smirnov, who was arrested in April on charges of embezzling funds intended for defending the border. He denies the charges. 

When Reuters visited Kursk in March, the size of the Russian military operation was striking: tanks, missile systems and thousands of soldiers were on the move while civilians spoke amid air-attack sirens of the fear of drone and missile strikes.

North Korean shells and troops helped Russia fight back in Kursk. Putin has expressed his personal gratitude to North Korean leader Kim Jong Un for his soldiers' help.

Russia's defence ministry says Ukrainian forces suffered more than 76,000 dead and injured soldiers in Kursk, and lost more than 412 tanks among several thousand lost military vehicles. Ukraine claims Russia suffered more than 62,000 dead and injured during the operations. Neither side has released numbers for their own casualties. Both sides dispute the numbers, which Reuters could not independently verify. 

OFFENSIVE 

As Ukrainian forces raced in August to expand their territory in Kursk, Russia scrambled units to the area to slow the advance and prevent Ukrainian forces from reaching the Kurchatov nuclear power station which supplies a chunk of electricity to southern Russia.

Within a month, the front had stabilised and Russia was able to counterattack.

"There were probably some very embarrassed Russian generals but it was a completely haywire incursion on the part of the Ukrainians - it was just mental frankly," David J. Betz, professor of war in the modern world at King's College London, told Reuters.

"Russia has a strong history of successfully defending itself but unlike luckier countries which are able to defend themselves with geography, Russia tends to have to defend itself with human bodies and distance," he said.  

Russian forces began gradually grinding down the defences of Ukrainian forces while Moscow unfurled thousands of fibre-optic drones, which are much harder to jam than other drones, Russian and Western sources said.

Within three months, Russia had more than halved the area under Ukrainian control and by February 6, the area held by Ukraine had fallen to 428 square kilometres, according to Ukrainian maps. 

By the third anniversary of its invasion of Ukraine, as Russian forces attacked, Putin donned military fatigues for a surprise visit to Kursk, ordering the top brass to press their advance and suggesting Russia carve out a buffer zone along the Ukrainian border.

In March, Ukraine lost more than 300 square kilometres of territory it had held in Kursk.

Valery Gerasimov, Russia's top general who is directing the war, told Putin on Sunday that Russia had cleared Kursk when the last Ukrainian units were pushed out of the village of Gornal beside the border.

He said Ukraine had stationed 60,000 troops in Kursk at the height of the operation, undermining its other forces, and praised North Korean troops for fighting "shoulder to shoulder" with their Russian comrades in arms in Kursk.

Gerasimov told Putin that in accordance with his orders Russian forces were "continuing" to carve out a buffer zone, and had taken 90 square kilometres of Ukraine's Sumy region.

Ukrainian officials have previously said Russian assault groups were present in Sumy. 

(Reporting by Guy Faulconbridge; Editing by Frank Jack Daniel)