- Russia's Yasen-class submarines have long been seen as a tough challenge for the US Navy.
- They are quiet and able to carry torpedoes as well as Kalibr and Oniks cruise missiles.
- A Russian shipbuilding official said that work is underway to arm them with Zircon hypersonic missiles.
The head of a top Russian shipbuilder revealed Monday that work is underway to arm some of Russia's most troubling guided-missile submarines with Zircon hypersonic weapons.