BEIRUT, Lebanon — For the first time, six years into a war that began with Syria’s secret police accused of torturing teenagers and has escalated in brutality ever since, a member of the Syrian military has been convicted of a war crime.

The perpetrator: a low-level soldier who is now in Sweden as a refugee. The crime: violating human dignity by posing with his boot on a corpse. The sentence: eight months in a Swedish prison.

Anticlimactic? At first glance, yes, for those who want Syria’s president, Bashar al-Assad, and other senior officials tried for far more serious crimes like using chemical weapons, bombing hospitals, and detaining and torturing tens of thousands of people.

Yet the ruling, issued last week in Sweden, is a landmark event, legal experts and human rights advocates say, the first conviction in any court of anyone from the Syrian government’s side for crimes committed in the multisided war.