In a little over a week, Ukrainians forces retook Izyum and dozens more occupied towns in a lightning offensive that shocked Western and Ukrainian officials with its speed, carrying almost all the way to the border, and sending Russian troops and pro-Russian separatist forces fleeing for their lives.

So far this month, Ukrainian officials say the military has reclaimed around 1,200 square miles of Russian-occupied territory in the offensive, which was enabled by Russia sending units to reinforce the south. Over the weekend, Ukrainian troops pushed into Izyum and Kupiansk, a major railway and transport hub in the east of the country that helped spur the Donbas offensive that Russian President Vladimir Putin declared in April. Kreminna, also taken by Russian forces in the spring offensive, had a Ukrainian flag flying over it by the weekend. In Lyman, which Ukraine regained on Saturday, troops entering the town reported that their Russian opponents virtually disappeared from their positions in the collapse. And Russian military leaders, seeing a remade battlefield in the country’s east, promptly fired the commander of the Western Military District overseeing the fighting.

“It’s a sign that Russia can be defeated,” Ukrainian Defense Minister Oleksii Reznikov told the Financial Times on Sunday.

Ukraine’s push was apparently the largest exchange of territory in the seven-month war, liberating in a matter of days most of the gains from Russia’s spring thrust into the Donbas, which saw most of Luhansk oblast fall into Kremlin hands. All of Kharkiv oblast is reportedly back in Ukrainian hands.

“The Ukrainian military’s counter offensive is moving faster and taking terrain even faster than expected,” said Mick Mulroy, a former U.S. deputy assistant secretary of defense. “It is clear that Russian willingness to fight at the foot soldier level is dropping.”

The offensive put Russian forces near Izyum at risk of being encircled, forcing their retreat. And the prospect of the main roads into the Donbas being under the watch of Ukrainian guns leaves the likelihood of Russia picking up its stalled offensive in the east as a moot prospect, Ukrainian officials said—irrespective of the trouble the Kremlin has faced in replenishing the ranks of its depleted military. British Defence Intelligence reported on Monday that Russia’s remaining troops in Ukraine were “highly likely” being forced to prioritize emergency defensive actions, and it assessed that trust of senior leaders within the ranks was likely to deteriorate further after the losses.

Russia’s defense ministry acknowledged the retreat in a statement on Saturday afternoon, but it framed it as a “regrouping,” taking troops from Balakliya and Izyum, which have fallen to Ukrainian forces in recent days, in order to reinforce Donetsk. Some Ukrainian officials said that part of the reason for Ukraine’s lightning success was in the weakness of some units left to defend the areas around Kharkiv, which included Russia’s National Guard equivalent, the Rosgvardia, and pro-Russian separatists from the Luhansk and Donetsk regions.

“They are poor,” Oleksiy Goncharenko, a Ukrainian lawmaker, said of the forces Russia had left behind near Kharkiv after reinforcing Kherson. “They’re not as strong as the army.” Another Ukrainian official said that Russian Wagner Group mercenaries and special operations forces had tried to avoid taking part in the war, for fear of getting chewed up in an artillery clash.

In Washington, Russia’s failure to quickly reinforce its troops raised questions from current and former officials about the state of troop morale, which U.S. intelligence has believed has been flagging for months—including frustration and sometimes retaliation at senior commanders for lack of preparation and information.

But Ukraine’s lightning success also brings some possible new risks. On Sunday and Monday, Russian forces attacked civilian power stations with precision rockets. Major cities such as Kharkiv, Dnipro, and Poltava were left without power. Critical civilian infrastructure can be a legitimate military target under the laws of war in some situations, such as when it has been converted for military use, but Russia’s strikes appeared to be purely retaliatory in nature.

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‘They Are Pushing Everywhere’: Kyiv Goes on the Offensive

Ukraine may have achieved its biggest breakthrough of the war.

REPORT |

JACK DETSCH

Ukrainian President Volodymyr Zelensky, despite the threat of more of his fellow Ukrainians facing an uptick of attacks against critical infrastructure, appeared to be in no mood to negotiate. “Do you really think that you can scare us, break us, make us make concessions?” Zelensky said in a Telegram post. “Don’t you understand who we are?”

The rapid advance of Ukrainian forces has also redoubled calls among Russian nationalists to launch a full-scale mobilization, which so far Putin has resisted, relying instead on contract fighters and conscripts already in the ranks. Such a step, while politically risky at a time of some signs of growing dissatisfaction with the conduct of the war, would pose challenges to Ukraine’s own troop situation.

Ukrainian officials and lawmakers, who have sought to reclaim as much ground as possible before winter sets in, have used the military turnaround to push for more military assistance to get to Kyiv. “We still have problems with ammunition,” said Goncharenko, the Ukrainian lawmaker. “The Russians are still firing more shells than we are. So that’s still the problem.”

On Friday, U.S. defense officials said that the Ukrainian counteroffensive had shown “encouraging signs,” but that they were still examining the global supply chain for NATO-standard 155 mm artillery batteries and had not made a decision on whether to supply armed Gray Eagle drones to Ukraine.

“Now is the time for every country supporting the Ukrainians to double down on their efforts,” said Mulroy, the former defense official. “Now is the time for the Ukrainian army to exploit every opportunity they have to degrade and destroy the Russian capacity to fight. The Ukrainians may be tired but the Russians are terrified.”