Creeping Sharia, via a commenter on this thread:
Richard Landes, in the post that began the discussion:
Whenever honor-shame rules assert themselves in civil society, the forces are badly matched unless the police is firm. In cases where the aggressors operate with impunity (essentially the situation in France), the pressure on civic communities will be either to get tribal (i.e., self-help justice), or to back off (which is what most français de souche are doing).
In this sense, it’s similar to the fall of the Roman Empire: tribal honor-shame, gang behavior coarsens the cultural scene and eventually brings down the rule of law as the areas where imperial writ runs retreat.
The parallel goes further. In the “experiment that got a little out of hand,” the Romans “invited” in the Germanic tribes and allowed them a legal advantage (a Frank or a Visigoths wergeld [manprice] was double that of a Roman. Similarly, the unofficial acceptance of Sharia puts the Muslim community at a tactical advantage in the daily conflicts.
This is how a civilization dies.
UPDATE: Richard Landes responds in the comments to criticisms of his Rome parallel.