Over here in America the only thing I think could fit in the pre-existing system for muslim is divorce court. I think the muslims need to set up between themselves these laws and follow them. FOr instance in Islam when a couple divorces it is incumbent upon the ex-husband to maintain the ex-wife for a three month term before he no longer has a responsibity to her. This allows that the woman can have time to get herself together and find means to support herself in the abscence of a husband. Since we are here in America, that is not American law. The law here has some semblance of that but its not the same, and consequently, since there is no authority established to make sure that happens as it should, many problems have arisen socially between us. I think we can incorporate a small court to handle those situations, or at minimum give the scholars of islam some governmental authority to implement and enforce that law and similar ones.
At the same time though, Islamic shariah is so vastly different from the system that non-muslim, secular governments have, that it would be quite impossible to incorporate them both. Islam covers wide gamuts of social and political interaction that one part is integral to the other, and so the implementation of some of shariah and the ignoring of other parts has always and will continue to be a failure.
I would like to draw the attention of those who oppose shariah law being passed in britain to the fact that this is the same thing that's been happening in ME countries for years. They have had to endure the putting in place of a system that was completely foreign to them. Unlike British citizens though, these people never had a chance to oppose it to any real effect. The same way you feel about the imposition of a foreign system of government and lifestyle ruling over you, is the same way the muslims feel about certain aspects of life they are not used to. It's the same thing, but people can't see that because they feel that western civilization is correct and better than most all other forms of government and ways of life, so therefore it is acceptable to impose this system on other even if it means toppling a whole government, and instead of allowing the people of the country to decide what kind of leader they would like, one is forcibly chosen for them. Imagine what it would be like if let's say Saudi decided to firstly invade britain, kill its leaders, kill its detractors, and then install a shariah government that you either must accept or leave the country. This is the same thing going on in muslim countries and it's why they are always upset.