At a time when Russia has built up forces on Ukraine’s border and fear of an invasion is running high, Mr. Zelensky has surrounded himself with people drawn from his comedy studio, Kvartal 95. Few have any experience in diplomacy or warfare.

“There is that risk of people not having the gravitas, and not having experience,” Orysia Lutsevych, the director of the Ukraine studies program at Chatham House in London, said in an interview. “I wouldn’t want to be in the room when there are just a couple of guys who know how to produce videos. This is not a peaceful time. This is a time of war.”…

Bihus, a Ukrainian investigative news site, has counted three dozen people with ties to Mr. Zelensky’s comedy studio and his family who are now in government, including in national security positions at the defense intelligence agency, which is tasked with monitoring the Russian buildup.

Mr. Zelensky has repeatedly rejected accusations of frivolity, and allies say his comedy background and wry humor are actually political assets.