Adapted from “The Diplomatic Path to a Secure Ukraine,” a paper that was published in February by the Quincy Institute for Responsible Statecraft.

More than two years into Russia’s invasion, it is increasingly clear that the Ukrainian army is not capable of reconquering the territories lost to Russia; instead, without continued and massive Western aid, the Ukrainians will suffer eventual defeat owing to Russia’s huge economic and demographic superiority, and the long-term continuation of such aid cannot be guaranteed. Sanctions have not cratered Russia’s economy or crippled its war effort. Russia has corrected many of the problems…