Gen. Oleksandr Syrsky, who was appointed commander of the Ukrainian military on Thursday, led two successful counteroffensives in the war against Russia before his troops became bogged down in one of the most contentious and costly battles of the conflict.
It was a strung-out, vicious spell of urban combat in the eastern city of Bakhmut last winter, and even as Ukraine was clearly losing ground in the fight, General Syrsky, then commander of the ground forces, had argued that the decision to defend was sound since Russia was losing more soldiers than Ukraine.
Ukraine maintained what military parlance calls a favorable attrition ratio in the Bakhmut street fighting, but it did little to win backers for the general’s strategy among rank-and-file soldiers. Bakhmut ultimately fell, after Ukraine had lost thousands of troops in the grinding fight.
The nickname “the Butcher” for General Syrsky is now widespread in Ukraine’s Army.
In the two earlier successful battles — in the defense of the capital, Kyiv, and in the northern Kharkiv region — General Syrsky’s soldiers had turned to small-unit tactics and rapid maneuvers to defeat the larger, better armed Russian forces. But it was his willingness to engage in attritional warfare over Bakhmut, however much the ratio of losses favored Ukraine, that drew criticism from the United States and that has hung over the general’s reputation in the Ukrainian Army.
General Syrsky is assuming command of the military after the front line has hardened, as rapid advances by Ukraine’s troops seem a distant prospect, amid deep uncertainty over the future of military aid from the country’s most important ally, the United States, and as a plan to mobilize more soldiers in Ukraine has stalled, complicating military planning.
How the general prosecutes the two-year-old war against Russia’s invasion will, in large part, be beyond his control, resting on what Western weaponry and new manpower will be at his disposal.
Still, Mykhailo Samus, director of the Ukrainian Army Conversion and Disarmament Center, a military research organization in Kyiv, said President Volodymyr Zelensky’s appointment to replace Gen. Valery Zaluzhny signaled a focus on ground combat. Ukraine must risk an advance and the costs in lives and equipment, Mr. Samus said, or be forced into a negotiation for a cease-fire or settlement on unfavorable terms.
When asked if the Pentagon had made contact with the new Ukrainian military chief, Brig. Gen. Pat Ryder, the Pentagon’s press secretary, said Secretary of Defense Lloyd J. Austin III had not spoken to General Syrsky. “One thing that won’t change,” he added, “is our continued support for Ukraine in their efforts to defend themselves against Russian aggression.”
General Syrsky, who will take command of Ukrainian forces in the largest war in Europe since World War II, was schooled in an elite military academy in Moscow before the collapse of the Soviet Union — and has spent much of his career fighting the Russians. He is intimately familiar with the tactics of his country’s enemy.
He began his career in the Soviet military in 1986; after joining the army of the newly independent Ukraine in 1991, he gradually climbed into the ranks of command. Between 2007 and 2014, he occupied several high-profile positions in the General Staff, and after Russia illegally annexed Crimea and fomented war in eastern Ukraine a decade ago, he was appointed as deputy commander of the Anti-Terrorist Operation, placing him in direct combat with Russian forces. In 2019, he became head of Ukraine’s ground forces, the post he held until his promotion on Thursday.
Complicating his command is the fact that he is taking a job vacated by a general who is well regarded by the army and the broader society, in what is widely perceived as a politicized shake-up of Ukraine’s military leadership.
Some soldiers and junior commanders in Ukraine’s military view General Syrsky as a holdover from an older generation, and say his embrace of a head-on fight in Bakhmut showed that he was pursuing bloody, Soviet-style military tactics against an enemy doing the same.
A Ukrainian platoon commander who has been fighting in the east on and off since 2014, and under General Syrsky since Russia launched its full-scale invasion in February 2022, said that the general had shown little willingness to adapt as new tactics and new technologies have appeared on the battlefield. He spoke on the condition of anonymity because he was not permitted to speak to the news media.
But the general has his supporters.
The battle for Bakhmut also enforced his reputation as a strong commander who leaves emotions aside, some say. General Syrsky, said Hanna Maliar, a former Ukrainian deputy defense minister, “has vast combat experience in this war.”
He has also worked closely with NATO on programs to modernize the army, beginning in 2013. And in the battles to rebuff the attack on Kyiv and clear out Russian forces from the Kharkiv region, he and his subordinates relied not on head-to-head infantry warfare, but on trickery and rapid maneuvers by small units.
General Syrsky commanded troops fighting against Russian forces and their separatist proxies in the eastern Donbas region starting in 2014. He directed the Ukrainian retreat there from the city of Debaltseve in 2015, which taught the military a bitter lesson in negotiated cease-fires.
In that battle, thousands of Ukrainian troops were partly surrounded by Russian forces, which had advanced close enough to the single access road to the city to open fire directly with tanks. To save the soldiers, Ukraine made political concessions in exchange for a cease-fire deal that Russia broke within days.
Rather than surrender, General Syrsky ordered soldiers to retreat at night under fire, and more than a hundred were killed in a harrowing dash over farm fields to reach Ukrainian lines.
In the current full-scale war, General Syrsky has shown he can fight despite lack of equipment and forces. In Kyiv, he commanded lightly armed troops fighting on the city’s outskirts, supported mostly by Ukraine’s Soviet-legacy artillery systems.
General Syrsky was selected for the top military position over a man considered his main competitor for the job: the commander of the military intelligence agency, Gen. Kyrylo Budanov, who had overseen a campaign of sabotage and drone strikes behind enemy lines and inside Russia.
These operations are asymmetrical, seeking to harm Russia using innovative tactics and technology such as drones that outweigh Moscow’s superior quantities of men and weapons.
“Zelensky has no choice but take any possible steps which will allow Ukraine to win,” Mr. Samus, the military analyst, said. “To base your military decisions on the people’s love is a mistake.”
Thomas Gibbons-Neff contributed reporting from London, Marc Santora from Kyiv, Ukraine, and Helene Cooper from Washington.