How to End a War That No One Is Likely to Win

For Kyiv, legally binding security guarantees—involving the United States, Russia, European countries, and potentially Turkey, as well—are crucial. Such guarantees would be the equivalent of extending NATO’s Article 5 to Ukraine: committing to go to war if Ukraine’s sovereignty or the terms of any potential agreement between Ukraine and Russia were violated. Such a pledge would certainly be a dramatic and precedent-defying step for the United States and its allies, which have tried to avoid being dragged into the war. Putin may not agree to it—or he may not agree to it in good faith. But binding guarantees—in contrast to the unenforced Budapest memorandum of 1994, which Russia first violated in 2014 by seizing Crimea—would furnish all sides with a solution to the essential problem of Ukraine’s security. Real bilateral or multilateral security guarantees would be better than NATO’s policy of having an open door in general but a closed door for Ukraine. Putin could sell this solution—the foreclosure of any chance that Ukraine would ever join NATO—as a win. At the same time, a U.S.-backed security guarantee to Ukraine could deter Russia from attacking Ukraine again.