Warning: this episode contains descriptions of violence.More than a hundred people died and scores more were wounded on Friday night in a terrorist attack on a concert hall near Moscow — the deadliest such attack in Russia in decades.Anton Troianovski, the Moscow bureau chief for The Times, discusses the uncomfortable question the assault raises for Russia’s president, Vladimir V. Putin: Has his focus on the war in Ukraine left his country more vulnerable to other threats?Guest: Anton Troianovski, the Moscow bureau chief for The New York Times.Background reading: In Russia, fingers point anywhere but at ISIS for the concert hall attack.The attack shatters Mr. Putin’s security promise to Russians.For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday.