The anxiety remains, but in Ukraine’s capital, large lines of cars are now forming on highways into the city and businesses are reopening. On Feb. 25, the day after Russia invaded Ukraine, Kolya Rybytva gathered his grandmother and younger sister and left Kyiv “quickly and without unnecessary sentiments,” he said, heading west. His parents and brother stayed behind to help in the war effort.“The decision was made in minutes,” he said, “and it was one of the most difficult in life, but we all understood that war does not provide comfortable solutions.”At the time, Mr. Rybytva, 24, understood that he...