Full of stoicism and unspoken fear, Ukrainian men steel for battle as they say goodbye to families

• More than 3 million Ukrainians have fled since Russia's invasion began on Feb. 24
• Ukrainian men, aged 18-60, have been prohibited from leaving the country to bolster war efforts.
• "I will never leave Ukraine." Millions of Ukrainian women have opted to stay behind with the men.

LVIV, Ukraine – Iryna Kotz calls her husband each morning to ask if the night was calm, even though she monitors the air raid sirens from hundreds of miles away through an app on her phone and knows calm is a rarity. When her children ask when they'll see their father again, she has no good answers for them.

As millions of Ukrainian women and children move west to escape Russia's widening war in their country, a largely unspoken front line – open-ended, full of searing psychological hurt – continues to expand across Ukraine: the men they leave behind.

Many of the women USA TODAY spoke to were too overcome with emotion to address the subject of leaving their husbands, but many Ukrainian men showed remarkable stoicism in talking about the pain of family separations that have no foreseeable end. They said it is their duty to defend their country.