Putin’s Threats Highlight the Dangers of a New, Riskier Nuclear Era
WASHINGTON — The old nuclear order, rooted in the Cold War’s unthinkable outcomes, was fraying before Russia invaded Ukraine. Now, it is giving way to a looming era of disorder unlike any since the beginning of the atomic age.

Russia’s regular reminders over the past three months of its nuclear might, even if largely bluster, were the latest evidence of how the potential threat has resurfaced in more overt and dangerous ways. They were enough to draw a pointed warning to Moscow on Tuesday from President Biden in what amounted to a tacit acknowledgment that the world had entered a period of heightened nuclear risks.

“We currently see no indication that Russia has intent to use nuclear weapons in Ukraine, though Russia’s occasional rhetoric to rattle the nuclear saber is itself dangerous and extremely irresponsible,” Mr. Biden wrote in a guest opinion essay in The New York Times. “Let me be clear: Any use of nuclear weapons in this conflict on any scale would be completely unacceptable to us as well as the rest of the world and would entail severe consequences.”