US boomer subs are incredibly stealthy and can operate anywhere in the ocean, including spending much time and effort practicing under arctic ice (see the Ice-X

US boomer subs are incredibly stealthy and can operate anywhere in the ocean, including spending much time and effort practicing under arctic ice (see the Ice-X series by SmarterEveryDay). I have no doubt US has the capability to camp subs under the ice, send launch codes via low frequency radio, surface and bring enough hurt to devastate Russia. The ability of Russia to effect a full decapitation first strike is on the order of nil.