Alexei Kozubenko’s 21-year-old son, Dmitry, an army private, was killed in action in March. Mr. Kozubenko declined to share details about where his son fought or how he died. An obituary in a local news outlet said he served in the 37th Separate Guards Motor Rifle Brigade, which Ukraine says was deployed in the suburbs around Kyiv before retreating last month.

Mr. Kozubenko, 51, served as a military officer, and Dmitry’s grandfather served too—though neither ever fought in battle. “There is a profession called defending your motherland,” said Mr. Kozubenko. “And if he didn’t die under a fence in a drunken or drug-addled stupor, or in a gang feud, but like a real man with a weapon in his hands, then that means it was an honorable death.”

Mr. Kozubenko said he supports the offensive. “But I’m opposed to it being so humane,” he said. “As soon as there is a single shot from a residential area, it should be leveled to the ground. If you treat people like animals, you should be treated the same.”