President Volodymyr Zelenskyy of Ukraine probably changed the fates of thousands of Ukrainian men when he signed a law lowering the draft age to 25 from 27 this month, more than two years after Russia began its full-scale invasion.

Ukrainian forces are struggling to hold back the far larger Russian army, and desperately need their ranks replenished. Now many of the young men who remain in Ukraine — thousands of others have illegally fled the country — worry about their future.

Reporters from The New York Times spoke to Ukrainian men who could be affected by the change.