May has been a particularly deadly month for the Russian military in Ukraine, with an average of more than 1,000 soldiers wounded or killed every day, according to U.S., British and other Western intelligence agencies.
But despite the losses, Russia is recruiting 25,000 to 30,000 new soldiers a month — about as many as are leaving the battlefield, U.S. officials said. This allowed his army to continue sending waves of troops against Ukrainian defenses, hoping to overwhelm them and break through the trenches.
It's a style of warfare that Russian soldiers have likened to being put through a meat grinder, with commanding officers seemingly unaware that they are sending infantry soldiers to their deaths.
At times, this approach proved effective, leading the Russian army to victories at Avdiivka and Bakhmut in eastern Ukraine. But Ukrainian and Western officials say the tactics were less successful this spring, when Russia tried to seize land near the city of Kharkiv.
American officials said Russia had achieved a key goal of President Vladimir V. Putin by creating a buffer zone along the border to make it harder for Ukrainians to attack the country.
But the attack did not threaten Kharkiv and was eventually stopped by Ukrainian defenses, according to Western officials.
“President Putin and Moscow really tried to achieve great things, to break through the front line this spring,” Jens Stoltenberg, NATO secretary general, said in an interview with the New York Times editorial board. “They tried and failed. They have made very small gains and are paying a very high price.”
Russian casualties increased at other times, especially during the assaults on Avdiivka and Bakhmut. But the attacks on those cities continued for several months. The May offensive, both outside Kharkiv and along the Eastern Front, involved more intense periods of waves of Russian attacks. British military intelligence analysts said Russia's casualties in May, which they estimated to average 1,200 a day, were the highest of the war.
Last month's fighting decimated the city of Vovchansk, about 40 miles from Kharkiv, where Ukrainians and Russians are engaged in a grueling battle for control.
Russian soldiers said on Telegram, the social media and messaging platform, that their units were suffering heavy losses. Some say their ranks were cut down by drones, machine gun fire and artillery barrages.
Russia's use of infantry in wave attacks reflects one of its advantages in warfare: Its population is much larger than Ukraine's, giving it a larger pool of potential recruits.
But the casualties have forced Russia to send new recruits to Ukraine relatively quickly, meaning soldiers sent to the front are poorly trained.
The lack of structured training and the need to commit new recruits to combat operations have limited Russia's ability to generate more capable units. It also increases casualties.
But it's more complicated than that. The changing nature of modern warfare has also increased the number of casualties in recent months.
The ubiquitous drones have made it easy for both sides to locate and target enemy forces. And mines and cluster munitions make movement in open terrain an almost suicidal undertaking.
Since Putin launched a full-scale invasion in February 2022, at least 350,000 Russian soldiers have been killed or wounded, Defense Secretary Lloyd J. Austin III recently said. British estimates put the number of Russians killed or wounded at more than 500,000.
US estimates of war casualties are based on satellite imagery, communications intercepts, social media and journalist cables, as well as official reports from Russia and Ukraine. But such estimates vary, even within the US government.
Reliable estimates of Ukrainian casualties are harder to come by. Ukrainian officials guard these numbers closely. Several US officials insist they do not have an accurate account. Zelensky has said that 31,000 Ukrainian soldiers were killed in the first two years of the war, but American officials say that number appears to undercount Ukraine's losses.
Russia conducted a partial mobilization in September 2022, which led to tens of thousands of young people fleeing the country. But Western intelligence analysts say Russia will not need to conduct another mobilization or draft this year.
Russia appears to be able to support its current campaign by offering financial incentives to recruits, attracting detainees and bringing some Russian mercenaries from Africa.
But the main question for this year will be whether Russia's current strategy will be able to beat the Ukrainian army, which is finding its defensive position. Weapons and ammunition from a new $60 billion U.S. aid package are finally reaching the front lines, and Ukrainian commanders no longer have to ration bullets. Russia still surpasses Ukraine in terms of weapons, but not by much.
Ukraine changed its position, building fortifications and laying minefields to slow the Russian advance. The war favors those who defend themselves and Ukraine is focusing on holding its lines, American officials said.
“What I see is a slowing of the Russian advance and a stabilization of that particular part of the front,” Austin told reporters in Brussels this month. “A couple of weeks ago there was concern that we might see a significant breakthrough from the Russians. I don't think we'll see that in the future.”
And Russia's new buffer zone on the border near Kharkiv may be a vain achievement.
Ukraine is still able to use long-range American weapons to strike Russia thanks to a policy change by the Biden administration that allows the Ukrainian military to use U.S. missiles to hit military targets just across the border.
American officials said the change was starting to have an impact, eliminating Russian artillery and making it harder for Moscow to strike Kharkiv.
The result, Ukrainian President Volodymyr Zelensky said this month, was that the Kharkiv offensive turned out to be “another mistake for Russia.”
“The destruction of Russian terrorist positions and launchers by our forces, our warriors, near the border is really important,” he said. “It works. Exactly as we expected.”
But for all of Ukraine's success around Kharkiv, there are more challenges ahead. In the coming weeks, U.S. and Western officials expect the fighting to shift east and south again, while Russia continues to appear willing to expend forces to make incremental gains.