Things haven’t been going smoothly for the Russian army in its attempt to crush the resistance in Ukraine and take control of the country. Casualties have been far higher than anticipated and progress has been slow. But while the Ukrainians have fought back bravely, Putin has continued to expand both the volume of forces moving into the country and the intensity of the attacks, going so far as to deploy banned thermobaric weapons. Barring some sort of diplomatic agreement to end the assault – which few analysts seem optimistic about – Ukraine may eventually fall. At the Wall Street Journal, Stephan Fidler examines the five key factors that military and intelligence analysts are watching when trying to predict how this all ends. Even the most likely “best-case scenarios” don’t look very good, but no matter what happens, this reckless invasion by Putin may still prove to be his undoing, and potentially the end of Russia as a global superpower.

Although predictions are next to impossible, military strategists are focusing on several factors to provide clues, including the performance of the armies on the ground and the impact of sanctions.

One thing becoming clear is that the performance of Russia’s military thus far is delivering Mr. Putin a reality check and potentially scrambling the range of outcomes. “Every day the Ukrainians don’t lose, they win politically,” said Michael Clarke, former director of the Royal United Services Institute, a London think tank. “And the political cost for him is going up on a daily basis.”

Lawrence Freedman, a professor emeritus of war studies at King’s College, London, doesn’t think the Russians will succeed in installing a puppet government in Ukraine. “They can’t occupy the whole country,” he said. “A puppet government in Kyiv not backed by Russian arms wouldn’t have any legitimacy and wouldn’t survive.”

Nobody expects Putin to look for or take an “off-ramp” out of this mess, or at least not yet. While it’s true that he may have severely underestimated the level of resistance he would encounter in Ukraine and vastly overestimated the competency of the military forces he deployed, Fidler points out that he has many resources that can still be brought into play. He may have to crush entire cities to break the current government, but there aren’t many indications that he won’t be willing to do so.

What then? Even if he tries to set up a puppet government in Kyiv, Russia will have to remain there in force for a very long time and virtually no other country will recognize it as being legitimate. If he simply declares that Ukraine is now a region of Russia, the massive sanctions against him and his cronies may never go away. Those burdens are already beginning to weigh on his people and that could create an unsustainable situation at home. He could eventually wind up being “removed” via one method or another. Is holding onto Ukraine really worth that cost?

So what happens if this situation somehow does wind up in regime change in Russia?. I don’t expect Putin, a despotic, violent KGB boss, to be suddenly replaced by some sort of light- bringing democratic savior. But they could at least gives a slightly younger, despotic, violent KGB boss who appears to retain more mental stability and predictable behavior than what we’re stuck with now.

The truly horrifying scenario that Fidler mentions is one where Russia attempts to try to close the border between Poland and Ukraine to block arms shipments coming from the west. It’s not unimaginable that this could lead to some military engagements across the border or on either side. At that point there would be NATO forces engaged with Russian troops and all of the safety mechanisms that should prevent this situation from massively escalating would become unstable. A full engagement of that nature would leave massive destruction in many places, but it would also very likely spell the end of Russia as we currently know it.

The best-case scenario being discussed involves the nascent peace talks between Putin and Zelensky’s people to be fruitful. Such a resolution might involve Ukraine giving up some additional territory in the east permanently along with a written promise to never apply for NATO membership. That might be enough to allow Putin to save face and fully withdraw. But few of the analysts quoted in the WSJ article seem hopeful that it will happen and many would find such Ukrainian concessions unacceptable. As I said, none of these scenarios look promising at the moment.