Only with strong and committed will.
10 October 732, the Battle of Tours. The Franks and Burgundians under Charles Martel had the will.
From the Battle of Covadonga in 718 or 722 to Isabella and Ferdinand kicking out the last of the Moors in 1492, Spain had the will for over 700 years.
Near Vienna on 12 September 1683. The Habsburg Monarchy, the Polish–Lithuanian Commonwealth and the Holy Roman Empire, under the command of King John III Sobieski, had the will.
Will we ever get the will to do the same? When? 2020? 2100? 2200? 2500? Do you honestly think the West is going to ever again have the will to survive and not commit suicide?