A war crime is defined as an action by an individual which goes beyond the rules of warfare, whatever they are, particularly as actions against civilians.  War Crime described by Wikipedia.

Russia’s war against Ukraine contains countless war crimes, such as shelling, bombing, and firing rockets into civilian residential areas.  Thousands of  civilians of the Ukraine have been killed by the Russian military.

Even though Ukraine has been a part of the Soviet Union and the people are not very different from the Russian population, there have been several attacks by Russia against her. 

In 1932-33 Joseph Stalin demanded the ‘collectivization’ of farms in the Ukraine.  Farms were taken from their owners, by force, and organized into communes.  The result was a deadly famine which killed an estimated 3.9 million people in the Ukraine.  See Holodomor: the Great Famine of 1932.

 In 2014, Russia invaded and annexed the Crimea, wresting it from Ukraine by force.  This followed resistance in Ukraine against Russian domination.   See Revolution of Dignity.  For a more complete story of the annexation, see Annexation of Crimea.

The current war against Ukraine is a war against a civilized, peaceful people, initiated  for no real reason.  Vladimir Putin, dictator of the Russian Federation,  is solely responsible for the killing of thousands of women, children, and peace-loving men, and the wrecking of homes and schools, and  the disruption of water, power, and the economy.

The full military power of a huge country is directed against an independent territory the size of Texas.  Russia has employed warplanes, cruise missiles, long range artillery, drones, and tanks against the Ukraine, which initially had none of these weapons.  The brutality of this is off the charts.  I therefore declare Putin to be a war criminal.  I wish the rest of the international community would follow suit.

In my opinion, as a war criminal, Putin should be subject to arrest and prosecution if he ever steps outside of Russia.  The verdict of the prosecution should be guilty, and he should be sentenced to death.