pentagon the pentagon official i spoke with today characterized it as sabre rattling. putin did this in february as well, right at the beginning of the invasion. this is the kind of talk that really alarms the biden administration and the united states has taken pains over the last few weeks to de-escalate and respond very carefully every time russian officials and vladimir putin start rattling their nuclear sabres. when you ask this question, katy, you are getting again, at the essence of what has kept the united states and nato countries out of this war, and that is at the end of the day russia has nuclear arms. his nuclear arsenal is in many ways all that vladimir putin has left, given how bismolly his