The aggressors are nearly always terrible excuses for humans, power-crazed egomaniacs isolated from reality and the truth, psychopaths pursuing delusions of grandeur regardless of advice or common sense or their impact on others.
Once things start going wrong for these people, their behaviour becomes less predictable and even more dangerous. It’s not for nothing they say never to corner a rat.
So does it really come as any great surprise that Russian leader Vladimir Putin is now overseeing an army engaged in abhorrent war crimes in Ukraine?
Mr Putin — though he barely deserves the courtesy of a "Mr" given his egregious and repugnant actions — has shown many times he has no empathy or compassion with the plight of those who find themselves in the firing line of his shambolic troops.
Increasingly appearing to be modelling himself on other butchering monsters such as Hitler, Stalin and Saddam Hussein, Mr Putin is showing scant regard for any of the accepted conventions of modern warfare.
In these, fighting is meant to take place between military groups and not be aimed at civilians, although they cannot fail to be drawn into skirmishes and become victims. That, of course, is an ongoing tragedy, but they are not meant to be the targets of the action.
However, in this war, withdrawing and demoralised Russian troops appear to be taking out their frustrations on the people of Ukraine in the most horrific ways.
Ironically, the very people Mr Putin’s propaganda claims he is trying to save from the clutches of "Nazism" are now the ones being found having been tied up and executed, almost certainly by the Russian army.
This is the same Kremlin which threatens to imprison its own people for not following its propaganda department’s guidelines in calling it a "special military operation" when clearly it is a war.
The reports coming from Ukraine now of the evil, casual brutality meted out to innocent civilians are heartbreaking and too shocking to believe.
The atrocities in the town of Bucha, near Kyiv, in which bodies have been left abandoned in the streets and where hundreds have been discovered buried in mass graves, should, we would hope, be enough to blow away the last vestiges of support for the Putin regime from countries such as China and India.
How anyone in their right mind could view these actions with anything other than pure revulsion, which would make them want to act against the perpetrators, is difficult to imagine. These truly are war crimes, crimes against humanity, crimes against everything which is decent and right, for which Mr Putin should pay.
Unfortunately, his spin machine will already be going full tilt trying to convince the gullible that the dead of Bucha — and probably other places yet to be discovered — have been planted there to discredit the Russian army. Surely nobody believes this stuff anymore?
United States President Joe Biden was earlier taken to task for his strong talk about Mr Putin, and for raising the idea that a regime change would be good. In the midst of all the rhetoric, the one comment which really rankled with the Kremlin was Mr Biden’s view that the Russian leader was a war criminal. Which he obviously is.
That particular sensitivity tells us something. Clearly, there are still some in Moscow who realise there is a line there and that such crimes, and the architects of them, step across that.
Mr Putin needs to be prosecuted, even if he claims he did not know what his soldiers were doing. And Russia needs to be removed from the United Nations Security Council.
Having shown no regard for the rules-based international order, it is a joke that it would still have a permanent seat on the council and a right of veto over the behaviour of others.
