‘Duty to warn’ guided US advance warning of the Moscow attack. Adversaries don’t always listen
![‘Duty to warn’ guided US advance warning of the Moscow attack. Adversaries don’t always listen](https://bloximages.chicago2.vip.townnews.com/lacrossetribune.com/content/tncms/assets/v3/editorial/1/f6/1f6096da-2405-5f0b-9ff0-811cb9af55b8/6604a5f031eb9.image.jpg?resize=300%2C200)
A little-known U.S. intelligence principle called the “duty to warn” came into play ahead of the deadly attack on Moscow’s outskirts. U.S. officials invoked that duty when warning Russian officials two weeks before Friday’s attack on a concert hall, which…