fundamentalist Islam is incapable of recognising any authority higher than Islam itself, and therefore rejects the authority of any secular state.

Say "deeply held beliefs" instead of "Islam". So do I. So did Rosa Parks. Or countless conscientous objectors. And you? Is there nothing you believe in and are prepared to break the law of the secular state for?

eurogreen:

What I want is distinct from what I expect the State to do on my behalf.

Intriguing. How do you expect your wish to come true? Ah, I have got it: probably you pray for divine intervention. ;)

eurogreen:

However, I don't wish for the state to somehow intervene to "reform Islam", or interfere with its practices, insofar as they stay within the law. That would be unwarranted interference.  I would prefer fundamentalist Islam to wither away, within France at least.

I can agree with that, provided the law is fair (which bans on women's clothes are not), and provided you don't single out Islam with your focus on fundamentalism.