The commander of the US Strategic Command, Admiral Charles Richard, spoke on possible nuclear war with Russia. 

According to his article on the U.S. Naval Institute journal Proceedings, "there is a real possibility that a regional crisis with Russia or China could escalate quickly to a conflict involving nuclear weapons, if they perceived a conventional loss would threaten the regime or state."

"Until we, as a [Defense] Department, come to understand, if not accept, what we are facing and what should be done about it, we run the risk of developing plans we cannot execute and procuring capabilities that will not deliver desired outcomes," Adm. Richard noted. "In the absence of change, we are on the path, once again, to prepare for the conflict we prefer, instead of one we are likely to face."