Julian Borger at the Guardian writes that:
A widening rift between Moscow and Washington over cruise missiles and increasingly daring patrols by nuclear-capable Russian submarines threatens to end an era of arms control and bring back a dangerous rivalry between the world’s two dominant nuclear arsenals.
It has been years since the U.S. and the USSR were locked in a contest to see who could accumulate the most weapons, best improve their lethality, and develop new methods of delivering them and defending against them. But there have been the widely reported provocations, the ratcheting up of tensions, the increasing belligerence of Putin, and the economic isolation of his troubled country. So now:
Tensions have been taken to a new level by US threats of retaliatory action for Russian development of a new cruise missile. Washington alleges it violates one of the key arms control treaties of the cold war, and has raised the prospect of redeploying its own cruise missiles in Europe after a 23-year absence.