The prodigal son was about how we should treat a contrite person who has sinned, but turns to Christ, not about Jihadists that want to come back to the west because they like it better than the hellhole they’ve chosen.
If ANY are allowed to come back it should be under 1 condition: Automatic prison time, and 2 TO NO ONE who has EVER murdered civilians of any religion, be they Syrian or Iraqi Jews, Christians, any other minor religion and Muslims of another sect.
the ONLY condition they should be allowed back under is a signed agreement to take the THIRTEEN STEPS solution, and the LONG DROP ON A SHORT ROPE.