The Soviet . . . .errr sorry Russian Avangard Missile is nearing operational status, US inspectors were invited to watch a demonstration of the missile under the START treaty which is due to expire in 2021.
https://www.newsweek.com/us-inspecto...fenses-1474182
The Avangard is a next generation hypersonic nuclear missile that travels faster then most bullets or about 1 mile per second. That basically means that a missile launched from Russia on Washington DC would take about 1 hour to arrive.
Hypersonic missiles will require a rethinking of current ballistic missile defense theory, both because of the speed of the weapon, and also because the glide vehicle itself is maneuverable unlike classic ballistic missile re-entry vehicles. This makes it a first strike capable weapon until defenses can catch up. It designed to decapitate governments, or to take out an enemies nuclear strike and war making capability before the enemy can respond.
https://en.wikipedia.org/wiki/Avanga...glide_vehicle)