Aflevering Russia’S Mystery Missile

At least seven people were killed by a mysterious explosion in northern Russia, and U.S. officials believe it happened during the test of a prototype for a nuclear-propelled cruise missile. President Vladimir V. Putin of Russia has hailed the weapon as the centerpiece of Moscow’s arms race with the United States — but what will this mean for an arms race that both countries want to win? Guest: David E. Sanger, a national security correspondent for The New York Times. For more information on today’s episode, visit nytimes.com/thedaily. Background reading: Intelligence officials suspect the blast involved a prototype known as Skyfall, a missile that Mr. Putin has boasted can reach any corner of the earth and evade American missile defenses.As the death toll has risen from the explosion, Russia’s silence and contradictory accounts have conjured dark memories of Chernobyl.