Talk we must about the prospects of a Russian tactical-nuke strike

While it is right to celebrate the Russian rout, the war may be entering a far more dangerous phase.

Consider: If Russian President Vladimir Putin tired of attrition and decided to use tactical nuclear weapons, how would Russian behavior—a rapid withdrawal and even leaving key equipment behind—be different? The answer: It would not be.

The Biden administration allowed fear of Russian nuclear weapons to self-deter and to limit deliveries of the weaponry that Ukrainian forces needed in the first weeks of the war. Fortunately, against the backdrop of Ukrainian perseverance, they recognized how unbecoming a policy governed by fear and weakness could be. That does not mean, however, that the United States and NATO should not have a contingency plan both to head off Russian use of nuclear weapons and respond to their use should Putin now cross the line. …

As the Ukraine war enters a crucial new phase, it is time both to step up deterrence and plan for what comes after Russian first use of nuclear weapons in Ukraine.