Russian President Vladimir Putin’s recent nuclear saber-rattling has not only unnerved the West. It has upset what’s known as “the world nuclear order,” a series of arms control agreements that undergird an international consensus that the use of nuclear weapons is to be avoided at all costs.

Putin’s not-so-veiled threats that Russia, if losing in Ukraine, might consider employing a “mini-nuke” to regain likely leverage deals a fatal blow to the notion nuclear weapons will be constrained with any new treaties.