Hafez Assad, the previous president of Syria, was a tyrant whose clan favoritism fractured the country and deeply disaffected many of its people.

His son and successor, Bashar, is infinitely worse — the author of crimes against humanity whose savagery and scale almost defy belief.

It is astonishing now to remember how completely the world misjudged him when he assumed power in 2000 after his father’s death.

A London-trained ophthalmologist fluent in English and beguilingly Western in manner and dress, he was seen as a possible agent of change.

The widely held hope was that under Bashar Assad, a country long failing by every sensible measure might at last be led toward a brighter future.

I don’t claim to have sensed the wrongness of those expectations. I fully shared them. But there was something about the man that troubled me — something really only cosmetic, yet disturbing all the same.

His was a weak face, with a mix of cruelty and cowardice in it. And the atrocities committed at Assad’s behest testify to the horrors that result when an unprincipled weakling holds absolute power.

The civilian dead — believed to number at least 30,000 in the last six months, and perhaps a great many more — are not collateral damage. They are calculated victims of Assad’s determination to cling to his failed presidency at whatever cost.

Accounts of shelling and aerial bombardment of residential districts, house-to-house searches by Syrian troops and their murder of the inhabitants, and the awful images of the innocent dead in open mass graves — these elevate the leader’s crimes to a special category of evil.

But his security forces are not the only villains.

Reports from the conflict tell of atrocities committed by members of the rebel movement, in which foreign and Syrian jihadis are believed to exert growing influence — offenses that include the deliberate killing of civilians and the summary execution of captured government soldiers.

Bashar Assad will fall. That much is certain. The question is what semblance of a nation might be made of the wreckage he will leave behind.

The hope is that he will not be felled by a shot from a rebel’s gun, but rather that he be taken alive, delivered to the International Criminal Court in The Hague and obliged to hear a recitation of the full catalog of horrors for which he is responsible.

Principal blame for the Syrian catastrophe rests with Assad, the U.N. high commissioner for human rights declared in Geneva on Sept. 10 — adding, however, that the anti-Assad forces “should be under no illusion that they will be immune from prosecution.”

Alone in their cells, Assad and the other principal offenders would have time to reflect on their likely fate before being taken before the tribunal to receive the verdicts and hear the sentences pronounced.

Surely Assad’s penalty would be death by hanging, unless some more satisfying method could be determined. I would hope that in the instant before the gallows trap was sprung, a new photograph could be taken of his face.

With power absent, the weakness and the cowardice should be fully apparent.