Robert de Neufville is a superforecaster and former Director of Communications of the Global Catastrophic Risk Institute. He writes and forecasts at Telling the Future.

Russia appears to have counted on a quick, decisive victory in Ukraine. Its goal was to quickly take Kyiv and other key targets, kill or capture Zelensky, and install a new regime friendly to Russia. If Russia could achieve its objectives within the first few days of the war—so that the conflict was resolved almost as soon as it began—the US and Europe would be unable to unify behind severe sanctions.

Russia’s plan depended on striking quickly, because it didn’t have the capacity to maintain an offensive on that scale and across three fronts for long. Unlike the US, which has a professional military capable of maintaining offensive operations indefinitely, Russia depends heavily on conscripts. Initially, Russia said it wouldn’t use conscripts in Ukraine: Generally they have less training and lower levels of readiness than professional contract forces. They can fight effectively in defense of their homeland, but are often reluctant to kill or risk their lives in an offensive war. In addition, Russia doesn’t have the trucks or logistical capacity to sustain a major offensive far beyond its borders.

It was a bad plan. Even if Russia had managed to reach Kyiv and remove Zelensky, its plan still probably wouldn’t have worked. It depended on Ukrainian forces and institutions essentially routing—and resistance to the Russian invasion collapsing—as well as on a Russian-installed leader being able to govern. It seemed so unlikely to work that many forecasters, including myself, had a hard time believing Putin would actually launch a full-scale invasion of Ukraine.

Russia eventually had to pull back from Kyiv after sustaining heavy losses. The war revealed the degree to which the Russian military was “gundecked," or made to seem it had been kept in a higher state of readiness than it actually had been. But if Russia was not as capable as it seemed, it is still more capable than it might seem now. It already controls about 20% of Ukraine. As I wrote in April, the spectacular failure of Russia’s initial invasion plan, which was highlighted by the sinking of the Moskva, the flagship of its Black Sea fleet, “should not fool us into thinking it’s nearly beaten or on the verge of collapse.”

Russia’s current objectives are more limited and more realistic: gain control of eastern and southern Ukraine. Ukrainian forces in the Donbas are outnumbered and outgunned, and Russia has been able to make steady gains against them. Russia should be able to establish and hold a land route to Crimea and to substantially block Ukrainian access to the Black Sea. I still think Russia and Ukraine will eventually reach a stalemate. Exactly where the final lines are drawn will depend on how long each side can continue. The war in Ukraine has become a war of attrition.

Russia has not given up on its broader war aims. Meduza reports Russia is considering making another attempt to take Kyiv if it can take control of the Donbas. Russia may believe that the US and Europe will eventually tire of supporting Ukraine, especially in the fall when Europe starts to need Russian oil and gas again.

But I’m skeptical Russia can mobilize enough additional troops to capture Kyiv or extend its control much beyond the Donbas. In theory, Russia could call up reservists from the general population, but in practice it would take time and would be extremely unpopular. At the same time, the US and Europe are strongly motivated to deter Russian aggression in Europe and see supplying Ukraine as a relatively cheap way to weaken Russia.

If Russia is unlikely to win a decisive victory, it’s also not likely to suffer a decisive defeat. Ukraine will also have a hard time finding additional capable troops to fight along the front lines. In spite of persistent rumors that Putin is dying or about to be overthrown, his hold on power appears strong. The Russian economy is strained, but it’s not on the verge of collapse. Ukraine hopes to wear Russia down, but in the absence of internal upheaval in Russia, it’s going to be hard to drive Russian forces completely out of Ukraine.

Russia and Ukraine don’t seem close to reaching a negotiated settlement either. The two sides haven’t met face to face since March and don’t appear to be negotiating at all now. Each side is hopeful it can outlast the other, and there don’t appear to be any meaningful concessions either can realistically give the other. When wars become wars of attrition, they tend to drag on.

I continue to see outcomes falling into four broad scenarios:

Military stalemate (64%): A military stalemate increasingly seems the mostly likely scenario. Eventually, Russia and Ukrainian forces are likely to settle into a stable equilibrium, with neither side making dramatic new breakthroughs. Russia will control substantial territory in eastern and southern Ukraine, but Ukraine won’t recognize Russia’s gains as legitimate. Russia will remain a pariah in Europe, although some sanctions will ease. Neither side will have much to gain from an agreement, so it could be years before a formal peace is negotiated.

Negotiated stalemate (25%): A negotiated end to the conflict seems farther off to me now. Neither side is under much pressure to reach an agreement right now. The US and Europe could pressure Ukraine to negotiate an agreement, but don’t seem to have any desire to do so. Ukraine is unlikely to agree to neutrality or recognize Russian claims to Crimea or the Donbas as long as it’s receiving weapons and supplies from the US and Europe.

Escalation (5%): Escalation seems less likely now that the war has settled into a war of attrition. Putin seems politically secure and has been willing to revise his goals instead of escalating. NATO has resisted public pressure to implement a no-fly zone, which would have meant direct conflict between NATO and Russia. There is some danger that supplying advanced weapons systems to Ukraine could lead to further escalation, but Russia has so far made no attempt to interdict the movement of weapons in NATO countries.

Russian defeat (6%): It is hard to see Russia withdrawing its forces completely without Putin being removed from power—and even if he were removed from power it’s not clear Russia would pull out of Ukraine. In the absence of any signs of imminent upheaval in Russia, a clear, decisive defeat of Russia seems unlikely.

Russia had hoped to land a quick knock-out blow against Ukraine. But it’s unlikely either side will win a clear victory any time soon. It’s an endurance contest now.