Ah, ok, as I said, I wasn't going to watch the video.
So you're not trying to justify the past murder and torture of a prisoner of war based on no actual evidence that he killed kids in an unrelated conflict, you're just justifying the threatened future murder and torture of a prisoner of war based on the the same unproven accusations about his conduct in an unrelated conflict. And even if these baseless accusations were true, it's still irrelevant.
If it's acceptable to torture and kill a member of an air force that killed children in a conflict, then it's acceptable to torture and kill every member of nearly every air force in the world.
There is no justification for torturing POWs. Period. And by adding in the 'Syrian child murder' accusation, that's exactly what you are doing.