As the investigation of reported rapes, executions and other potential war crimes showed after Russian troops withdrew late last month from northern towns such as Bucha, near the capital Kyiv, possession of sites is all important. With its dominance in Mariupol, Russia has a freer hand in its efforts to control and present any findings on what happened there.

That’s become increasingly important for the Kremlin as only in Mariupol has there been even a notional basis to paint Russia’s invasion as — in President Vladimir Putin’s words — a “noble” effort to rescue ethnic Russians from fascism. The city is where the right wing Azov battalion, a former volunteer militia with an infamous insignia similar to the Nazi-appropriated “Wolfsangel,” has fought to the end.

Avoiding a larger repeat of the Bucha revelations — and indeed accusing Mariupol’s Ukrainian defenders of crimes — is now a critical focus for Putin’s messaging machine at home.