Well, he didn’t quite put it like that, but it’s pretty much what Cardinal Robert Sarah. meant!
Robert Sarah (born 15 June 1945) is a Guinean Cardinal prelate of the Catholic Church. A Cardinal since November 2010, he was appointed as Prefect of the Congregation for Divine Worship and the Discipline of the Sacraments by Pope Francis on 23 November 2014.
Interviewer: There is a religion in the world that doesn’t seem to be experiencing a crisis and that is growing. Do you fear confrontation with Islam?
Cardinal Sarah: I hope you are not giving the word “confrontation” a warlike or conflict-oriented sense. War is the work of the Devil and his children. What worries me most is that Islam is encountering only a decadent West, secularised, irreligious and immoral, and therefore a West that offers no spiritual resistance. Statistics show that in the very near future there will be a cultural, religious and demographic imbalance in the West. The West, decadent, without children, without families, will disappear, submerged and eliminated by a population of Islamic origin. The West has renounced its Christian roots. But a tree without roots dies.