Volodymyr Zelensky did not hide his distress as he surveyed the rubble of Bucha. "Every day, you understand, there are people found in barrels and cellars, strangled," he said, struggling to hold back the tears. "Indeed, this is a genocideThe annihilation of a people, either through killing of its members, or through the suppression of its culture.."

The Ukrainian president's words and pained face cover newspaper front pages around the world.

As Ukrainian forces recapture areas of the country that were occupied, they have found horrifying evidence of war crimes. Civilian corpses strewn across the streets showed signs of summary executionsSystematic killings without a trial.. Satellite images appeared to show a mass grave.

What do these grim discoveries mean? For one thing, they are evidence of crimes against humanity.

Some argue the treatment of ordinary Ukrainians may reveal a truth about the way Vladimir Putin understands the war. It may suggest the invasion is not to gain control of disputed territories. It is an attack on the very idea of Ukraine - and Ukrainians. 

An article published this week in the Russian state news agency gives an insight into how Russian leaders justify the war. It falsely states that Ukraine has become "Nazified". Calls for "European development" and "independence", the article says, are in fact an attack on Russians and Russian speakers living in Ukraine.

The article's solution to this imaginary situation? A war, followed by 25 years of occupation and the erasure of Ukraine.

It carries echoes of statements Putin has made.

Shortly before the invasion of Ukraine, Putin gave a speech in which he outlined his understanding of the relationship between the countries. "Ukraine is not just a neighbouring country for us," he said. "It is an inalienable part of our own history, culture and spiritual space."

Putin believes Ukraine became a separate country as a result is a historical accident. He grants the country no legitimacy.

Even if Putin's was right, it would not justify war and massacre. And historian Timothy Snyder points out that there are major errors in his account. "Ukraine has its own distinct and fascinating history," he says.

While it is wrong, Putin's account may explain Russia's treatment of Ukrainians: he sees them as a threat to the idea of Russia and does not accept that the country has a right to exist.

Yes: Putin's beliefs and ambitions cannot survive contact with hard realities, however uncompromising they are. This war is costing Russia heavily in military and economic terms, and at some point, he will have to seek peace.

No: An absolutist worldview like Putin's permits no compromise. Russia's aggressive and expansionist behaviour will only end once he is removed from power.

Or... No war lasts forever and there are too many variables to confidently predict what path this one will take. But whether or not there is a peace settlement, Putin's aggression has already undermined peace and stability in Ukraine and beyond.