f the most prominent Catholic authors of his time--gives a common sense explanation of why the Crusades were necessary, and why they ultimately failed. He argues that the personal and strategic failings of the First Crusade's leaders led to the establishment of a state that could not be sustained, and that the absence of such a state left Europe vulnerable to Islamic aggression for centuries afterward. Writing in 1937, following the demise of the Ottoman Empire, Belloc believed that the West had finally gained the advantage over its mortal foe. However, he also includes a prophetic warning to Western Civilization, about the eventual resurgence of Islam and its enduring desire to destroy Christendom.