After a year of heavy losses, Ukraine's military is juggling a 'very uneven' force as it prepares for major fighting, expert says

• Ukraine's military is gearing up for offensives against Russian forces in spring and summer.
• Ukraine has taken heavy casualties, but its military has grown due to recruitment and mobilization.

Following Russia's illegal annexation of Crimea and the start of the war in the Donbas in 2014, the US and other NATO militaries began training the Ukrainian military to prepare it for a large-scale conflict.

That conflict kicked off on February 24, 2022, when tens of thousands of Russian troops lunged for Kyiv and other major cities. Ukraine thwarted their initial attack within a few days, but the fighting has dragged on for more than a year.

As the war has gone on, rising casualties among Ukraine's Western-trained troops and the mobilization of reservists who were trained under Soviet military doctrines have created a force with differing levels of experience and differing understandings of how units in the field should operate.

A wartime military

When Russia invaded in February 2022, Ukraine's military had about 196,000 active personnel and 900,000 in reserve, according to the International Institute of Strategic Studies' 2022 Military Balance report.

Ukraine declared a general mobilization shortly after the invasion, and its military has swelled since then. According to the 2023 Military Balance report, Ukraine now has an active-duty force of 688,000 with 400,000 in reserve and 250,000 in its police and paramilitary forces.

Ongoing combat and call-ups mean troop numbers are hard to determine. Ukraine has not released official casualty numbers, but recently leaked US intelligence documents put them at 15,500 to 17,500 killed and 109,000 to 113,500 wounded.

Ukraine's military "has now expanded significantly, but it's also taken significant losses over the course of the past year," Michael Kofman, director of the Russian Studies Program at the CNA research organization, said on a mid-March episode of the War on the Rocks podcast.

Kofman, who spoke shortly after visiting Ukraine and the conflict's frontline, said that talking to soldiers at different levels gave him the impression that "many of the best people have been lost."

"You often lose your best people in war first," Kofman said. "Many of the folks who are trained by NATO between 2014 and 2022 have been lost too. A lot of junior leaders have either been lost or have been rotated up and promoted. So there's a lot of churn."

"What I see in that military is that it's just very uneven," Kofman added. "It's very uneven because there are folks that have come from civilian life and some have had a bunch of training and some had very little."

The Western approach

Beginning in 2015, the US Army, forces from other NATO members, and partner militaries worked under the Joint Multinational Training Group-Ukraine to train over 23,000 Ukrainian soldiers for a large-scale conflict against Russia.

Their aim was to forge "a new kind of NATO-compatible professional fighting force in Ukraine," a US official said in 2021. The training they provided accompanied other efforts by Kyiv to reverse two decades of post-Cold War decay that weakened the Ukrainian military.

Western allies worked closely with Ukrainian forces to identify areas where they needed the most training. Ukrainian troops in company- and battalion-level units participated in numerous exercises in Europe and received training in Western arms, small-unit tactics, and doctrine.

Developing Ukraine's noncommissioned officers — enlisted troops who have experience but haven't been commissioned as officers — received particular focus.

Western training created "a competent non-commissioned officer corps that could feed initiative and make tactical decisions based on commander's intent," similar the role of NCOs in NATO militaries, Lt. Col. Todd Hopkins, deputy commander of the Florida National Guard's 53rd Infantry Brigade Combat Team, which participated in the effort, said last year.

Western doctrine gives junior leaders significant freedom to implement decisions that come from the top and encourages them to take the initiative. This approach is especially effective when troops are familiar with the battlefield, as were many Ukrainians who had been fighting Russians and Russian-backed forces in the Donbas since 2014.

Ukrainian military leaders have highlighted this flexibility as a major factor in their effectiveness against Russian forces who, much like the Soviet military, rely on senior leaders for direction and instructions in combat.

As important as that flexibility is, the "churn" caused by combat losses and rounds of mobilization mean it is not uniform across the force Ukraine is now fielding. Differences in the training these troops have received are also creating friction.

Two armies in one

Yet, as casualties among Ukraine's NATO-trained troops increase and as Kyiv calls up more of its older reservists who were trained according to Soviet standards, parts of the Ukrainian military are coming to resemble that of Russia, according to Kofman.

Some of these older troops have "come back to senior positions across different staff levels, and they are of a different culture," one that is more like "what the Ukrainian military may have been in the past," Kofman said on the podcast.

This has created two forces within the Ukrainian military, he added, one of them flexible and able to make decisions across the command level and the other more rigid. The result is a kind of a military culture clash that may impact how Ukrainian units perform in offensives Kyiv is expected to launch in the spring and summer.

This is "fundamentally a difference of culture between a military that does mission command and things like that by default," Kofman explained, referring to Ukraine's Western-trained troops, "and then also a Soviet army that's well embedded in this military and has its foot in the past."

"This is a continuous struggle in the Ukrainian military," Kofman said.

Constantine Atlamazoglou works on transatlantic and European security. He holds a master's degree in security studies and European affairs from the Fletcher School of Law and Diplomacy. You can contact him on LinkedIn.