Mr. Katsiurin is not alone in his frustration. When Valentyna V. Kremyr wrote to her brother and sister in Russia to tell them that her son had spent days in a bomb shelter in the Kyiv suburb of Bucha because of the intensive fighting there, she was also met with disbelief.

“They believe that everything is calm in Kyiv, that no one is shelling Kyiv,” Ms. Kremyr said in a phone interview. She said her siblings think the Russians are striking military infrastructure “with precision, and that’s it.”

She said her sister Lyubov, who lives in Perm, wished her a happy birthday on Feb. 25, the second day of the invasion. When Ms. Kremyr wrote back about the situation on the ground, her sister’s answer via direct message was simple: “No one is bombing Kyiv, and you should actually be afraid of the Nazis, whom your father fought against. Your children will be alive and healthy. We love the Ukrainian people, but you need to think hard about who you elected as president.”