The risk that a Russian invasion of Ukraine by conventional forces could lead to the use of nuclear weapons appears relatively low, but their shadow is never completely absent from a crisis involving nuclear-armed states. Moreover, this crisis—no matter how it ends—seems likely to lead toward more strategic instability, not less. As preoccupied as U.S. diplomats must be with the threat of imminent conventional invasion, they must also work urgently to launch confidence-building… – Defense One Photo: US Army