"Armed militants threaten Europeans in cartoon uproar "
When you allow a hornets nest into your home, you are bound to get stung.
What Europe has done over the past century or so, and especially in the last few decades, is to reject its Christian heritage and embrace secularism. During that time, it has prided itself on its so-called "tolerence", and has had some of the most liberal immigration laws in the world. That, combined with collective guilt over its colonialist past, has allowed Europe to become a haven for millions of Muslims, mainly from North Africa and the Middle East.
As Muslims moved into Europe, they brought their religion and culture (which are really inseparable) with them. Now that they have reached critical mass, the Europeans are starting to "reap the whirlwind". The vast majority of Muslims do not understand the freedoms of the West, nor do they want to embrace them. They want freedom to practice Islam, and they want everyone else to practice it (or submit to it) with them. When you defy them, they will make you pay. The Europeans (especially the French and the Dutch) are finally starting to realize that.
It will be really interesting to see how this plays out. American secularists should learn from the mistakes of the Europeans.