The threat of the radical Islamists taking over Europe is every bit as great to the United States as was the threat of the Nazis taking over Europe in the 1940s. We cannot afford to lose Europe. We cannot afford to see Europe transformed into a launching pad for Islamist jihad. While we in the United States and Europe have vast resources for protecting ourselves, we have thought ourselves into a position of near impotence. Beyond the growing number of Muslims committed to terrorism is the threat from the Islamic diaspora's growing cultural and religious assertiveness -- particularly in largely secular Europe, where Muslim cultural assimilation has not occurred. It is beginning to dawn on Europeans that the combination of a shrinking ethnic-European population and an expanding, culturally assertive Muslim population might lead to the fall of Western civilization in Europe within a century. This phenomenon, called Eurabia, is viewed with growing fatalism both in Europe and in America. Such fatalism, however, is premature. Europe's effort at cultural tolerance since World War II slowly morphed into a surprisingly deep self-loathing of Western culture that denied the instinct for cultural and national self-defense. If Europe doesn't rise to the challenge, Eurabia will come to pass. Then Europe will cease to be an American ally and instead become a base of operations (as she already is to a small degree) against us.Muslim sections of Paris, Rotterdam and other European cities already are labeled "no-go zones" for ethnic Europeans, including armed policemen. As the Muslim populations -- and their level of cultural and religious assertiveness -- expand, European geography will be "reclaimed" for Islam. Europe will become pockmarked with "little Fallujahs" that effectively will be impenetrable by anything much short of a U.S. Marine division.