Last September, a few weeks before Ukraine’s general election, Arseniy Yatsenyuk, then as now prime minister, issued a pamphlet listing his aims. One was stark: “To get through the winter.” Given that rebel soldiers in the eastern part of the country paint “To Kiev!” on their tanks, that Ukraine relies on Russia for much of its energy, and that its economy is in dire straits, it is nonetheless safe to say that he has succeeded. The rebels, despite inflicting two major recent defeats on the government forces, have not advanced significantly. Winter power cuts in regions unaffected by the war were short and survivable. Also, while the current cease-fire, agreed to on February 12, is not expected to last, Ukraine and its government have not collapsed, nor do they show any signs of being on the brink of doing so, as some of the Russian media keep saying hopefully.

As winter turns to spring, soldiers on both sides of the front line are anything but tired of the war. Spirits are high and demoralization and exhaustion have not yet set in. Both sides are better organized than before and their commanders are trying to second-guess where the other will attack when the cease-fire breaks down completely, as they all assume it will soon. If and when it does, there are three main possible outcomes. The first is that the rebels, with the Russian support they need, will take more territory and, depending on how easy it is for them to advance, will push north, west, and south as far as they can. The second is that the Ukrainians will retake territory and push the rebels back, but this can happen only if Vladimir Putin decides not to help the rebels any longer. The third is that even with the front line moving somewhat one way or another, the conflict will morph into a frozen one.

In the latter case, the self-declared Donetsk and Lugansk People’s Republics together will become a giant version of all the other post-Soviet frozen conflicts, such as Transnistria in Moldova or Abkhazia and South Ossetia in Georgia. In these places Russia is in de facto control of slices of other countries, but they have not much of an economy or prospects of a brighter future for their people, and so the young and dynamic leave. We cannot know what Putin may decide to do, but right now this third outcome seems the most likely.

There is a big gap between what leaders on either side want and what is attainable. On the Ukrainian side the maximum…