In 1938, the year of Anschluss and Munich, a perceptive British Catholic looked beyond the continent over which war clouds hung and saw another cloud forming.
"It has always seemed to me ... probable," wrote Hilaire Belloc, "that there would be a resurrection of Islam and that our sons or our grandsons would see the renewal of that tremendous struggle between the Christian culture and what has been for more than a thousand years its greatest opponent."
Belloc was prophetic. Even as Christianity seems to be dying in Europe, Islam is rising to shake the 21st century as it did so many previous centuries.
Indeed, as one watches U.S. armed forces struggle against Sunni insurgents, Shia militias and Jihadists in Iraq, and a resurgent Taliban, all invoking Allah, Victor Hugo's words return to mind: No army is so powerful as an idea whose time has come.
The idea for which our many of our adversaries fight is a compelling one. They believe there is but one God, Allah, that Muhammad is his prophet, that Islam, or submission to the Quran, is the only path to paradise and that a Godly society should be governed according to the Sharia, the law of Islam. Having tried other ways and failed, they are coming home to Islam.
What idea do we have to offer? Americans believe that freedom comports with human dignity, that only a democratic and free-market system can ensure the good life for all, as it has done in the West and is doing in Asia.
From Ataturk on, millions of Islamic peoples have embraced this Western alternative. But today, tens of millions of Muslims appear to be rejecting it, returning to their roots in a more pure Islam.
Indeed, the endurance of the Islamic faith is astonishing.