Russia abruptly fired a front-line general, and now Ukraine is seizing the moment to punch through the defenses he had overseen

• Ukraine appears to have launched a major attack in the southern Zaporizhzhia region.
• The surge, reported on by media and officials, marks a dramatic escalation of Kyiv's counteroffensive.
• Ukrainian forces had been conserving combat power as they navigated through Russian minefields. 

Ukrainian forces reportedly launched a massive push against Russia's front-lines in the country's southeastern Zaporizhzhia region, threatening Russian positions that had been overseen by a general who was recently fired. 

The surge marks a dramatic change in pace for Ukraine's ongoing counteroffensive. For nearly two months, Kyiv's troops were forced to make slow and steady advances to liberate occupied territory as they faced Russia's formidable defensive lines, which include deadly networks of trenches, barbed wire, anti-armor obstacles, and minefields. 

Clearing the Russian fortifications — particularly the minefields — has been a painstaking process for Ukraine, which managed to preserve lots of its firepower and combat capabilities, such as heavy armor provided by the US and its NATO allies. But it now seems as though Kyiv has committed significantly more resources into the fight. 

Pentagon officials told the New York Times on Wednesday that Ukraine has poured thousands of reinforcements — many who have been trained and outfitted by Western countries — into battle along the Zaporizhzhia axis, which is one of several locations along the several-hundred-miles-long front line where Kyiv is fighting.

The sheer scale of this thrust as reported suggests a main attack has begun, coming after weeks of probing attacks and mineclearing that suggests Ukraine's war commanders think they've found a vulnerable spot in Russia's formidable defenses. The fired Russian general had demanded changes after suffering losses in artillery battles with Ukraine that were crucial to holding their defensive lines.

According to the US officials, Ukraine has expressed a desire to press south toward the occupied city of Melitopol, near the Sea of Azov. Doing so would allow Kyiv's military to split the territory that Russia currently occupies and threaten its hold on the Crimean peninsula.

Russian state-run media outlet TASS said Ukraine carried out a "massive tank attack" in the Zaporizhzhia area, citing a defense ministry official, who claimed the attacks had been repelled and that Kyiv lost a number of tanks, armored vehicles, and personnel. The battlefield picture, however, was disputed and unclear on Wednesday, and Insider was not able to immediately verify Moscow's assertions.  

Ukrainian officials did not publicly reveal many details about the new push on Wednesday, although Kyiv's General Staff of the Armed Forces said in a Facebook update that Russia "is concentrating its main efforts on preventing the further advance of our troops" in Zaporizhzhia.

The General Staff added that Ukraine's air force carried out over a dozen strikes on Russian troops, military equipment, weapons, and anti-air defense systems. It said Kyiv's missile and artillery units managed to strike Russia's own artillery units and command posts. 

"By the way, today our guys at the front had very good results. Well done. More details later," Ukrainian President Volodymyr Zelenskyy said in his address to the nation on Wednesday. 

The new Zaporizhzhia assault comes shortly after Russia's military leadership fired Maj. Gen. Ivan Popov, who previously commanded Russia's 58th Combined Arms Army, which had been battling Ukraine's offensive in that region. Popov was apparently dismissed from his role earlier this month after he raised concerns over several front-line weaknesses plaguing his forces, including deficiencies in Moscow's artillery defense.  

Popov later said in an audio message that he raised concerns about "the lack of counter-battery combat, the absence of artillery reconnaissance stations, and the mass deaths and injuries of our brothers in enemy artillery fire." Lacking air superiority, Ukraine has relied heavily on artillery to strike Russian troop positions, command and control locations, communications sites, and heavy guns. 

According to the Times, Ukrainian officials told the US that the new operation in Zaporizhzhia could take up to several weeks. Kyiv's military leadership previously expressed frustration with some in the West who have suggested that the counteroffensive should be moving faster than it had been, saying that every meter of territory is extremely costly for Ukraine to liberate. Top Pentagon officials have also pushed back on discourse around the speed of the offensive. 

"The various wargames that were done ahead of time have predicted certain levels of advance. And that has slowed down," Chairman of the Joint Chiefs of Staff Gen. Mark Milley told reporters at a briefing last week. "Why? Because that's the difference between war on paper and real war. These are real people in real machines that are out there really clearing real minefields and they're really dying."

Milley said at the time that Ukraine had been preserving its combat power while its forces slowly make their way through Russia's elaborate minefields, which the US general referred to as Kyiv's biggest threat — and the source of many of its casualties. It's unclear exactly how much of that combat power has now been committed in Zaporizhzhia.

"This is going to be long, it's going to be hard, it's going to be bloody," Milley said last week. "And at the end of the day, we'll see where the Ukrainians end up, vis-a-vis the Russians."