If NATO forces cross into Russian territory, that might provoke a nuclear response from Moscow. “There is a possibility that if Russian forces are sufficiently degraded or defeated in Kaliningrad that Moscow may resort to or threaten nuclear first use,” Kofman wrote. “Nuclear escalation is not assured, but given the impact of such an outcome, perhaps the best strategy is to make decisions that afford the most opportunities for managing escalation dynamics. That means a force posture oriented toward strategic flexibility, not entrenchment.” Such a war will almost certainly escalate into a full-up nuclear war between the planet’s only two nuclear superpowers—which means everyone loses.

This piece first appeared in 2017 and is being reprinted due to reader interest.