But to apply the special case of negotiation — with few parameters and a narrow range of outcomes — to a complex, fluid and much wider geopolitical rivalry is a category error. While the danger of Russian nuclear escalation may rise and should be studied carefully, there is no special, separate category of actions that the West or Ukraine might take that would automatically trigger it. Russia has no red lines: It has only, at each moment, a range of options and perceptions of their relative risks and benefits. The West should continually aim, through its diplomacy, to shape these perceptions so that Russia chooses the options that the West prefers.
America did this before. During the Cuban missile crisis, the most dangerous nuclear confrontation so far, the Soviet Union’s position shifted in a matter of days, ultimately accepting an outcome that favored the West. Had red-line thinking been in vogue, America might well have accepted an inferior compromise that weakened its security and credibility.
While Russia is more invested in subordinating Ukraine than it was in deploying missiles to Cuba, the logic is the same. In 1962, America persuaded the Soviet leader, Nikita Khrushchev, that removing nuclear weapons from Cuba was, however unpalatable, a better choice than deploying them. Similarly, the West should now aim to persuade Mr. Putin that withdrawing his forces from Ukraine is less perilous than fighting. He will be likely to do so if he understands that a long war threatens his regime — whose preservation seems to be the only thing he values more highly than a subordinated Ukraine — by fatally weakening domestic cohesion or by escalating out of control.
America should focus on three things. First, it should no longer declare that there are measures it will refrain from taking and weapons systems it will not provide to support Ukraine. To signal unilateral restraint is to make an unforced concession. Worse, it emboldens Russia to probe for and try to impose further limits on U.S. action — making the war more, not less, risky.
Second, America, with its partners, must make clear that time is working against Russia — not in its favor, as Mr. Putin still believes. The West should demonstrate readiness to mobilize, and quickly, its huge economic superiority to enable Ukraine to defeat Russia and to impose further severe sanctions. The military and economic costs to Russia will drain its far more limited resources and place greater strains on the regime.
Third, the West should make clear to a wide range of Russian audiences that it is safe to end the war by leaving Ukraine. An orderly withdrawal is unlikely to lead to regime change, let alone the breakup of Russia. Neither outcome is an official goal of Western policy, and talk of them is unhelpful and even counterproductive. Some in the West will resist the idea of any such reassurance. But if Russia’s elites conclude that it is as dangerous for Russia to leave Ukraine as to stay, they have no incentive to press for an end to the war. Reassurance does not mean compromise.
Pursued firmly and resolutely, these diplomatic shaping operations in support of Ukraine’s military campaign can ensure that Russia’s least-bad option aligns with what the vastly more powerful West wants. Such a strategy is the opposite of accepting red lines. Revealingly, red lines are the mirror image of an earlier metaphor used at the start of the war. When Russia looked strong, many proposed giving Mr. Putin an offramp to persuade him to stop fighting. Now that Russia is weaker, they call for Western restraint to persuade him not to fight more recklessly.