We have to get it through our heads that the problem is not so much "them", but "us". We are not Christian countries... even amongst "conservative" Catholics/Christians there is a very strong commitment to social-modernism (c.f. Leo XIII, Libertas, Pius XI, Quas Primas).
We can hardly blame Islam for filling a spiritual void. If the "West" wants to commit suicide - whose fault is that? If the "West" refuses to reproduce itself etc., etc. we cannot blame Islam. We must blame ourselves.
Leo XIII prohpetically pointed out in Immortale Dei:
To exclude the Church, founded by God Himself, from life, from laws, from the education of youth, from domestic society is a grave and fatal error. A State from which religion is banished can never be well regulated; and already perhaps more than is desirable is known of the nature and tendency of the so-called civil philosophy of life and morals. The Church of Christ is the true and sole teacher of virtue and guardian of morals.