The U.S. wants Kyiv to lower its draft age to 18 — risking dire demographic consequences. Can Ukraine’s army manage without it?

U.S. President Joe Biden’s administration has been urging the Ukrainian authorities to lower the country’s mobilization age from 25 to 18, according to American officials who spoke to Reuters, the Associated Press, and The Financial Times. The White House reportedly believes the measure is necessary for bolstering the ranks of the Ukrainian Armed Forces (AFU) amid Russia’s successful offensives in Donbas, the Kharkiv region, and other parts of the front.

“The simple truth is that Ukraine is not currently mobilizing or training enough soldiers to replace their battlefield losses while keeping pace with Russia’s growing military,” one senior official reportedly told FT.

These anonymous officials’ statements aren’t the only indication of U.S. pressure. Last week, White House National Security Advisor Jake Sullivan stated explicitly that the White House believes that “Ukraine needs to do more […] to firm up its lines in terms of the number of forces it has on the front lines.” A month earlier, Zelensky chief of staff advisor Serhiy Leshchenko also mentioned that Washington was trying to persuade the Ukrainian president to lower its mobilization age (though he said Zelensky “had not given in”).

We don’t know. What is clear is that Kyiv estimates its current minimum requirements at 160,000 new recruits, while the Biden administration considers this the “lower limit” of the AFU’s actual needs.

Ukraine already tightened its mobilization policy back in the spring of 2024. Among other things, it lowered the mobilization age from 27 to 25 and abolished the category of “partially fit for service.”

At the time, Volodymyr Zelensky and other top Ukrainian officials predicted the changes could potentially bring in up to 500,000 new soldiers and officers. However, the authorities never publicly disclosed the specific parameters of the new mobilization effort, so it’s unclear exactly how many people have joined the Ukrainian army in the last six months.

We know that before the start of Russia’s full-scale invasion, there were approximately 200,000 people in Ukraine’s army. Based on statements from Ukrainian officials over the last three years, we can estimate that the number of personnel in the army would currently be around 1.25 million without accounting for losses. According to estimates from The Economist, Ukraine has lost between 60,000 and 100,000 soldiers, including both deaths and severe injuries. Therefore, in the worst-case scenario, even taking into account the new mobilization law passed in the spring, the size of the Ukrainian army could be as low as 750,000.

This is roughly equivalent to the most recent estimates from the Russian authorities of the number of Russian servicemen fighting in Ukraine: in the summer of 2024, Vladimir Putin said that there were about 700,000 Russians at the front.

At the same time, The Financial Times, citing data from the Verkhovna Rada’s economy policy committee, gave a more optimistic estimate of the number of Ukrainian troops: 1.2 million.

In any case, when Ukraine tightened its mobilization policies earlier this year, journalists from the outlet Texty.org.ua estimated the country’s mobilization reserve at 5.1 million people. Given the U.S.’s concern about the Ukrainian army being understaffed, we can assume that even such a large “on-paper” reserve was insufficient to replenish the army to a level capable of turning the tide on the battlefield.

According to estimates from Texty.org.ua, which rely on projections from Ukraine’s Ptoukha Institute for Demography and Social Studies, lowering the mobilization age to 18 could add a little more than 434,000 people (without taking into account student exemptions). For comparison, the category of men ages 25–26, who were subject to the latest mobilization wave after the previous policy change, amounted to an estimated 273,300 potential new soldiers.

However, it’s important to note that mobilizing even younger men is not just unpopular in Ukraine but could also be disastrous for the country’s future. Because of the low birth rate in the initial years after the collapse of the Soviet Union, the number of men in this younger age group is significantly smaller than the currently middle-aged generation, who were born during the Soviet era. (The same is true in Russia.)

In other words, enlisting men younger than 35 to join the war could exacerbate the demographic crisis already intensified by the war — whether through battlefield casualties or population loss due to emigration. Volodymyr Zelensky’s reluctance to heed requests from Ukraine’s largest ally to call up 18-to-34-year-olds is understandable. The real question is whether the U.S. will take Ukraine’s demographic challenges into account in its demands.