At some point, the issue of NATO’s further enlargement will have to be settled. It is crazy to trigger a war for the principle of a cause—Ukraine’s possible membership in NATO—that isn’t actually going to be enacted. There must be ways to defuse the dispute without surrendering the principle. NATO could issue a statement explaining the many reasons Ukraine is not eligible for membership today. Experts could be consulted on how long it would take for this to change. In tandem with these steps, Biden and other Western leaders should hold behind-the-scenes talks with Ukrainian President Volodymyr Zelensky, offering a boatload of security assurances and economic goodies, in exchange for his withdrawing his request for NATO membership—on the condition that Russia withdraws its newly mobilized tanks and other weapons from the Ukrainian border.

Will this be easy? No. Diplomacy is hard, especially when the disputes and conflicts of interest are as complex and deep as they are here. Will everyone be satisfied with the outcome? No. Ukrainians would like the warm-blanket security of NATO’s Article 5 guarantees. Russians (not just Putin) would like the uncontested restoration of their “sphere of influence” to the west. They’re not going to get these things.