It's the demography!
Emmanuel Todd and Youssef Courbage, an intellectual and a demograph, have written a book The rendez-vous des civilisations (a title that I would translate as "The civilizations will unite"), which takes an opposite view of the much controversial book by S. Huntington The clash of civilizations.
In this book, that I have not read but which is reviewed by Pierre Assouline, it is argued that Islam, which is at the center of the "problem", is, contrary to what we might think, already on its way of being westernized, and this is deduced by a pure look at the demography of muslim populations: the birth rate passed from 6.8 to 3.7 child per women between 1975 and 2005. The thesis is the following: the intellectual and cultural evolution of a people depends much on its demography than on its mood. In particular, the highest the birth rate, the more powerful religion is and inversely. Apparently, this lecture fits well the evolution of christian people in Europe and the authors argue in their book that this is what is happening as well in muslim nations. Thus, for them, the future is bright, and the different civilizations are already on a road of convergence.
Although optimist, this book has nonetheless received many criticism regarding the simplicity of their theory and the lack of cultural factors to judge the future. Critics that I think are well founded. But it is worthy and courageous to give a different perspective, one which contradicts the much too fearful theory of S. Huntington.