Four years into a grinding war her nation never asked for, Ukrainian first lady Olena Zelenska has the bearing of a woman who has seen the worst the world can offer. But there is no resignation in her eyes, and during a nearly one-hour interview on a visit to Dallas last week, the wife of Ukrainian President Volodymyr Zelenskyy made clear that her mission on behalf of her country’s children is only just beginning. One of the nastiest elements of the unimaginably brutal war Russia has waged on Ukraine is something too few Americans seem to remember, if they ever...