Oil is a commodity...
...and one of the factors of commodity pricing besides demand is...supply. Reliable supply.
It doesn't matter how large a share Saudi has if they are not delivering the goods in a predictable, stable fashion. They eitehr will fix their problems or they won't.
There will certainly be some shock to the system if we withdraw BUT if it is done in a rational fashion, IE gradually over a years time say, then the markets will adjust and adapt in a reasonable fashion as would we all if the local convenience store was closing up, selling less goods each month until ceasing entirely.
The goal here is for Saudi to be a good international citizen and Saudi has this responsibility because they have, at present, such global power. They must be held responsible if for no other reason than the fact that we all stop using the convenience store if we're getting mugged because they do not police their grounds.
As far as France goes, it's a small, socialistic nation and trains work for socialists. We're big. We have an interstate highway system and we're Americans. We like our own train so to speak.
The point was that there are reasons France is not very helpful in the Middle East. Lower oil dependency is a huge one.
The fact remains that Saudi is the source of the vast majority of international terrorism.