KYIV -- When Ukrainian soldiers tore a poster with the Russian flag from a billboard in Balaklia, a city in the Kharkiv region that was liberated on September 8, they unexpectedly revealed a poem by Ukraine's foremost 19th-century poet, Taras Shevchenko, beneath.
"Keep fighting -- you are sure to win!" read the words of one of his most famous pieces, titled The Caucasus and written more than 150 years ago to glorify the national liberation struggle against the Russian Empire.
The phrase, which in recent months has become a popular wartime slogan, reflects the enthusiastic mood prevailing across Ukraine after Kyiv's lightning offensive in the Kharkiv region that led to the near-total collapse of the Russian line of defense there.
The success of the operation surprised even Ukraine's defense minister, Oleksiy Reznikov, who told the Financial Times that the operation had gone "better than expected."
Now, as the picture of what happened is becoming clearer, RFE/RL spoke with several Ukrainian military analysts about what happened and what to expect next.
Success Brings Challenges
"I believe that Reznikov might have been indeed surprised with our army's success," Ukrainian military analyst Mykhaylo Zhirokhov said. "Usually, operations of such scale would be carried out by at least six brigades, whereas Ukraine engaged from three to four brigades there."
According to Zhirokhov the aim of the initial blow by Ukrainian forces was very well chosen: they first attacked the poorly trained militias mobilized from the recently occupied Ukrainian territories and then units of Russia's National Guard, which are usually used to suppress demonstrations and have limited combat experience. When the Russians tried to bring up regular troops, it was already too late and the chaotic retreat was in full swing, he says.
When Ukrainian troops took control of the key northern cities of Kupyansk and Izyum in just four days and reached the Oskil River two days later, the Russians had no chance to redeploy troops from other areas.
This was only possible because Russian commanders were taken completely by surprise. Beginning in early August, Kyiv was broadcasting a counteroffensive in the Kherson region, prompting Russia to shift some of its best forces to the south.
Due to the informational blackout imposed by the Ukrainian authorities in the zone of military action, the public has limited and delayed knowledge of Ukrainian advances. At the moment, fighting is reportedly still going on around the city of Lyman in the Donetsk region, and on September 12 Ukrainian forces confirmed they had liberated Svyatohirsk.
But the rapid successes bring new challenges. Most likely, Ukraine will soon need an operational pause in places where it recaptured territory, Zhirokhov says. "When the left flank of the units in Slovyansk and Kramatorsk is fully protected, Ukraine's military will have to focus on securing logistic and defense structures on the 6,000 square kilometers it has recaptured," he explained.
South Still The Key
Meanwhile, the focus of confrontation could return to the south.
"Although the attention of observers has now shifted to the Kharkiv region, the key to the future of the war still lies in the south," security expert Pavlo Lakiychuk told RFE/RL.
According to Lakiychuk, by moving its troops to the western bank of the Dnieper River, Russia not only reduced its forces in the northeast, but also left them in a position that is becoming increasingly dangerous.
Over the past month, Ukrainian forces have repeatedly cut the two bridges across the river and crippled Russian efforts to resupply their forces via barge and pontoon ferry.
Ukrainian forces have also recently made significant territorial gains in the south -- about 500 square kilometers of territory over the past two weeks, according to the Operational Command South spokeswoman Natalya Humenyuk.
"The Kherson counteroffensive was never a feint," Lakiychuk said, "but its logic is the opposite of the Kharkiv operation."
In his view, Russia would be better off if it retreated to the eastern bank of the Dnieper, but domestic political considerations prevent this. Ukrainian commanders are using this strategic mistake to systematically weaken the capabilities of the Russian troops trapped on the western bank.
"The effect will be the same as in the northeast: Russian soldiers will be left to their own devices by their command and will either surrender or try to flee," Lakiychuk added.
According to Humenyuk, some Russian units in the Kherson region have begun trying to negotiate a surrender to Ukrainian forces after they learned about the failure around Kharkiv. "The degree of creaking resolve and demoralization is so high that even the commanders now realize they don't have anywhere to go," she said on September 12.
'We Just Need To Keep Going'
Most Ukrainian military experts agree that after last week's counteroffensive, the Russian goal of capturing the entire Donetsk region is no longer feasible, and thus the Kremlin needs to come up with a new agenda.
"Ukraine has once again thwarted Russia's plans, exactly as in late March and early April when, after the Battle of Irpin, Ukraine regained control of the entire Kyiv region," Ivan Stupak, a former Ukrainian Security Service (SBU) officer and military expert at the Ukrainian Institute for the Future, told RFE/RL.
"It is telling that Russian official media could not swallow these developments before they were able to report about the bombing of our energy infrastructure," he added, referring to Russian rocket strikes against civilian electrical and water facilities that were reported in the Kharkiv, Sumy, Poltava, Zaporizhzhya, and Dnipropetrovsk regions on September 11.
According to Stupak, Russia will intensify its shelling of power plants, heating stations, and electrical transmission lines. And it will continue to exploit its control over the Zaporizhzhya nuclear power plant to "terrorize and blackmail Ukrainian society." But such tactics reveal Russia's strategic weakness, he argues.
"The Kremlin is not able to announce a mobilization, and [Russian President Vladimir] Putin seems to be losing control over what is being said on Russian state television," Stupak said. "The initiative is clearly on our side; we just need to keep going."