"Most Ukrainian men ages 18 to 60 have been banned from leaving the country.... There are exemptions — fathers with three or more children can leave, as can people with medical issues. There are also ways to sneak out...."

"Some men said they took exit routes that were illegal.... 'We just wanted to live... We ran from hell. Like Stalingrad in 1942.'... A 24-year-old [medical student] from Kyiv... ran through a field and then a forest, 'scared s---less,' he said, until he and the others ended up on a cold road in what happened to be Moldova.... The medical student received papers giving him the legal right to be in Moldova. There’s just one thing missing: a Ukrainian exit stamp. 'So I don’t know how I can go back,' he said. ... In Chisinau, at the army barracks, a 32-year-old IT employee from Kyiv said he and his father, 57, had managed to cross without any problems. They presented non-Ukrainian passports. The catch is that in Ukraine, dual citizenship is illegal. The 32-year-old said he had talked with his dad at length about whether they were doing the right thing, and they agreed that war had forced them into a terrible, cold decision: picking their own interests above those of their country. 'I don’t feel like a traitor,' the son said. He said it was natural to choose self-preservation. 'Just like America,' the father said...."

From "In a war of terrible choices, these are the fighting-age men who left Ukraine" (WaPo).