In 732 AD, Moorish forces under the command of Abd al-Rahman advanced from Spain toward the capital city of Paris. They met a force of Franks under the command of Charles Martel. Three days later the Islamic commander was dead and his much diminished army was heading back to the South. This was the Battle of Poitier, and if it had gone the other way it is likely that all of Europe would now be Muslim and history would be very different.
But in present day Europe the Islamic forces have advanced much further than Abd al-Rahman. In France there are Muslim communities where the police will not go, and now the violence from those communities is spreading into central Paris. In Belgium the police are told not to be seen drinking coffee during Ramadan. In Sweden there are communities where ambulances need a police escort to protect them from radical Muslim violence. In Spain Islamic studies are now taught in the public school curricula. In Denmark radical Muslim youths are burning cars and torching shops and threaten the lives of newspaper reporters and editors critical of Islam. In Holland the native Dutch are beginning to leave their own country in fear of the radical Muslim communities there that are no more integrated with Dutch society than they were three decades ago when they first arrived, members of which have murdered prominent Dutch critics of Islam.
It is a pattern seen all over Europe, all over the world. Radical Muslims move in, taking advantage of the liberal immigration laws, but won't integrate with the rest of society and eventually stop respecting the existing government. They form de facto governments of their own responsive to them and their own traditions and eventually press for seperation as an Islamic state, as was the case in Nigeria, or a complete takeover. And they are often murderously violent toward the host culture, seemingly unwilling to get along with their neighbors.
Of the dozen or so major conflicts in the world today, almost all of them involve Muslims who can't get along with their neighbors. And in almost all cases the Muslims are the aggressors.
It's a World War, and we are losing it. Our nominal allies, the Europeans, have in some cases already bowed to the inevitable and are suing for peace. Europe is descending into a new Dark Ages with permanent conflict.
The French government thought that a policy of appeasement, such as in refusing to join in the Iraq war, would win them peace and keep the problems confined to the ghettos, but the radical Muslims saw that for what it was, a sign of weakness. In fact, the violence has been going on for months now with 9000 police cars stoned since the beginning of the year and three dozen cars torched even on a quiet night. But now the violence has spilled out into Paris itself, and it will not stop in the forseeable future. The French police have already declared themselves overwhelmed.