Those who support American military intervention in Ukraine are in essence asking that NATO call Russia’s bluff. They don’t believe that Putin would nuke American forces in the field. And perhaps they’re right. Would he really risk Moscow and St. Petersburg to preserve his hold on Kyiv? We just don’t know.

But I’m afraid this argument insufficiently addresses the logic of tactical nuclear warfare. If he deploys tactical nuclear weapons, Putin would be calling our bluff. Given our limited tactical nuclear arsenal, would we escalate to the use of strategic weapons in response? Would we risk Washington and New York to dislodge Putin from Ukraine?

Given Putin’s expansive tactical nuclear arsenal—and given the very live debate over his willingness to deploy that arsenal to block NATO intervention and (theoretically) force an end to the war before a truly apocalyptic escalation—the Biden administration’s strategic choices since the invasion make a great deal of sense.