Ukraine is short of soldiers and debating how to find the next wave of troops

Soldiers fight in icy, muddy trenches bombarded by artillery, or in a warren of burned and blown up houses during urban fighting. The casualty rate is high and there are many dangerous missions, such as storming enemy-occupied tree lines.

While planning a renewal of Ukraine's military under extreme conditions, both the country's former top commander and his replacement have highlighted the same looming problem: the need to relieve exhausted, battered troops whose combat tours have lasted nearly two years .

In a tumultuous week for Ukraine's war effort, President Volodymyr Zelensky removed his commanding general, General Valery ZaluzhnyThat happened Thursday as aid from the country's largest source of arms and ammunition, the United States, remained in doubt in Congress.

While Ukraine depends on its allies for weapons, replenishing its ranks is a domestic challenge. Small protests have erupted against a proposal by Parliament to extend the proposal to younger men, although Parliament has so far been slow to implement the measure.

Military analysts have largely coalesced around the idea that Ukraine will, at best, hold existing front lines in ground combat this year with a new influx of U.S. weaponry — and risk falling back without it. It plans to replenish its ranks through mobilization while keeping Russia off balance with long-range drone strikes and sabotage operations behind enemy lines and within Russia.

Announcing the appointment of General Oleksandr Syrsky as army commander, Mr Zelensky said he wanted a “new management team” for the armed forces. He has signaled a search for a new strategy that takes into account exhausted frontline soldiers in Ukraine's million-strong army, which is fighting Europe's biggest war since World War II.

He proposed a partial solution by sending more soldiers into battle from rearguard positions, but he also signaled “a new approach to mobilization and recruitment,” without elaborating.

Mobilization had been a factor in General Zaluzhny's dismissal. The plans to call up more soldiers to fight in grim trench warfare were something no one in Ukraine's military or civilian leadership wanted to be associated with. General Zaluzhny and Mr Zelensky had been in open, public disagreement over the mobilization since December.

Mr. Zelensky said at a news conference in December that General Zaluzhny's staff had asked for 450,000 to 500,000 troops to be called up, a comment that seemed designed to shift responsibility to the military for a decision to call up so many more soldiers , said opposition politicians.

General Zaluzhny responded that the decision to call up more soldiers was not up to the army. He said the armed forces have made estimates of their manpower needs to allow for rotations of those currently serving, replace soldiers killed or wounded in battle and anticipate future losses.

“We need grenades, weapons and people,” General Zaluzhny said. “Everything else is done by the agencies that have the authority.”

In a statement after his appointment on Thursday, General Syrsky listed “military lives and health” among his priorities and said the Army would seek a “balance” for units between frontline deployments and training.

On this extremely sensitive issue for Ukraine, “unity has disappeared,” Iryna Friz, MP from the opposition European Solidarity party, said in an interview. “The issue of mobilization was sabotaged for politics.”

The draft law on mobilization was adopted by the Ukrainian parliament in its first reading. It would lower the draft age from 27 to 25 and toughen penalties for draft dodgers.

Ukraine is currently calling for men between the ages of 27 and 60. Under martial law, all men between the ages of 18 and 60 are prohibited from leaving the country, otherwise a decision will be made to draft them.

Men with three or more children are exempt, but men with three children or fewer who volunteered or whose families expanded during their service are not allowed to leave the military.

The bill in parliament also allows for the demobilization of troops after three years of service, offering the prospect of a reprieve in about a year for soldiers who have fought since the 2022 invasion. The law is expected to be passed this month and will come into effect in March, Yaroslav Zhelezniak, a member of the opposition Holos party, wrote on Telegram.

For men eligible for military service, trench warfare is a harrowing prospect. Soldiers die from artillery, exploding drones and snipers and in close combat with Russian forces. Russia's ubiquitous landmines have blown off the legs or feet of thousands of Ukrainian men. And bunkers where soldiers slept last winter were overrun by rodents attracted to the warmth of the tree trunks or rough wooden structures, worsening unpleasant conditions at the front.

Soldiers at the front typically sleep in shifts in trenches and bunkers under fire for about three days, followed by three days in less risky reserve positions, such as abandoned houses in nearby villages.

Ms. Friz, the lawmaker, said the Ukrainian government and parliament should design the draft to balance the needs of the military and the economy and maintain political stability, all issues beyond the scope of the military's duties.

For example, lowering the conscription age would bring more flexible, healthy soldiers into combat, but poses long-term risks to sustaining Ukraine's future population, given the country's demographics.

Like most former Soviet states, Ukraine has a small generation of twenty-year-olds, as birth rates plummeted during the deep economic depression of the 1990s. Because of this demographic low, there are now three times as many men in their 40s as in their 20s in Ukraine.

Using more men in their twenties, given the likely war casualties, would risk decreasing the number of births in this small generation of Ukrainians, resulting in a decrease in the number of men of draft age and in working age decades from now, which would jeopardize the country's future security and economy.

In one effort to address the concerns of men who are drafted but want to have children, Parliament is considering a bill to pay medical bills for soldiers who want to freeze their sperm so partners can become pregnant if they are killed in combat.

Ukraine's workforce has already been massively reduced by the exodus of women fleeing war and the mobilization of men.

A crowd angry about the march blocked a road outside a western Ukrainian village last week in a rowdy confrontation with motorists and police, illustrating the political risks of expanding the mobilization.

Villages in the west have been a primary source of soldiers for the Ukrainian army, and support for the war has been greater in the west of the country than in Ukraine overall. But the loss of male loved ones has taken its toll on many families.

The roadblock took place on Tuesday in the village of Kosmach, Ivano-Frankivsk region, and started with unfounded rumors in local chat groups that conscription officers were coming to look for the village's remaining men, police said in a statement. About a hundred women blocked a road and the protest turned violent when they mistook a woman from a neighboring village for a conscript, police officers said.

The woman, Ivanna Vandzhurak, wrote in a Facebook post that the crowd had shouted that she was a “spotter” for the local military recruiting office. The accusation reflected widespread concern in Ukrainian society that spies in their midst, known as spotters, help Russia identify missile targets, but in this case the source of the fear was the military recruitment system.

Dmytro Mokhnachuk, the chairman of a council that governs the village and nearby communities, told local news media that the women agreed to disperse but told him they were “fighting conscripts.”

Maria Varenikova contributed reporting from Kiev, Ukraine.