Ukraine-Russia conflict: Who is a war criminal and who gets to decide?

Glass on a hospital window is shattered by shelling in Mariupol, Ukraine (Evgeniy Maloletka/AP)

US President Joe Biden has flatly called Russia’s Vladimir Putin a “war criminal” for the unfolding onslaught in Ukraine, where hospitals and maternity wards have been bombed.

But declaring someone a war criminal is not as simple as just saying the words. There are set definitions and processes for determining who is a war criminal and how they should be punished.