NATO meets in Madrid on June 28. As the West’s peace camp increases its din, it’s a good moment to consider the consequences of a Ukrainian defeat. They would be catastrophic. Any peace that secures Russian assent will be tantamount to Russian victory. Russian victory will divide and in time destroy the Atlantic Alliance, severely weakening the United States’ long-term position in Eurasia. Putin may not have entered this war with grandiose ambitions vis-a-vis NATO. But his war has become his defining policy action. The West should understand that Russian victory would fundamentally transform the Eurasian order.