In a momentary turning of the tables, a seemingly unprecedented Ukrainian ground incursion into Russia signals a new type of attack that is causing alarm in Moscow.
Up to 1,000 Ukrainian troops, driving tanks and other armoured vehicles and supported by drones and artillery, are reported to have charged across the border into Russia’s Kursk region in the west of the country on Tuesday.
Russian forces were still countering the assault near the border town of Sudzha on Thursday, with thousands of residents forced to flee.
Russian President Vladimir Putin accused Kyiv of a “large-scale provocation” – even though his forces were the ones to launch a full-scale invasion of Ukraine in February 2022 and have been waging a bloody and devastating war ever since.
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The Ukrainian government has stayed largely silent about the situation – but an adviser to Ukraine’s leader, Volodymyr Zelensky, wrote on social media that the Kremlin and its actions in Ukraine was to blame for any counterattacks on Russian territory.
“The root cause of any escalation, shelling, military actions, forced evacuations, and destruction of normal life forms, including within [the Russian Federation’s] own territories like #Kursk Belgorod regions, is solely Russia’s unequivocal aggression,” Mykhailo Podolyak wrote on X.
He added: “Russia has consistently believed that restrictive legal norms do not apply to it, thus it can attack neighbouring countries’ territories with impunity and hypocritically demand… the inviolability of its own territory. But war is war, with its own rules, where the aggressor inevitably reaps corresponding outcomes.”
The Ukrainian military incision, if confirmed, would be the first and largest known attack by members of the armed forces of Ukraine.
Previously, limited cross-border ground assaults into Russia have been claimed by volunteer groups comprised of Russian citizens who have chosen to fight alongside Ukrainian forces.
The development comes as Ukraine has been stepping up drone and missile attacks against military targets inside Russia – including with western weapons.
It also took place as Kyiv and Moscow try to strengthen their positions on the battlefield ahead of this November’s US presidential election.
The United States under President Joe Biden and vice president Kamala Harris has been a pivotal supporter of Ukraine, providing weapons and funding that are crucial in enabling the Ukrainian military to counter Russia’s offensives.
There are concerns this could change should Donald Trump win the presidential race. He has said he would end the war in one day.
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The reason for the cross-border incursion into Kursk is not yet clear.
It could be a move by Ukraine to try to draw Russian forces away from frontline positions in the eastern Donbas region or in northeastern Kharkiv, where Moscow has been trying to make gains.
However, with Ukrainian troops already stretched, the opening of such an audacious new frontline inside Russia could rapidly suck up much needed weapons and soldiers.
General Valery Gerasimov, Russia’s top military commander, is reported to have said about 100 Ukrainian soldiers had been killed in the battle and more than 200 wounded. But these figures have not been independently verified.
Disinformation and propaganda are used as weapons in the war.
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Whatever the calculations, the situation has clearly caught the attention of Mr Putin.
He met with top defence and security officials and instructed his cabinet to coordinate assistance to the Kursk region, which is about 320 miles from Moscow.
The region shares a 150-mile border with Ukraine, making it possible for saboteur groups on either side to launch incursions and capture ground before being repelled.