The three Muslim gunmen who killed 12 journalists in Paris targeted not just those people and their satirical magazine Charlie Hebdo, but a core ideal and human right of the West––the right to free speech in the public square defined by tolerance for different opinions. That's why the killers, after they had called out the names of their individual victims before they shot them, bragged as they made their escape that they had "killed" Charlie Hebdo. That's why they also cried, "The Prophet has been avenged," since the magazine had frequently spoofed Mohammed, most famously in its reprinting in 2006 of cartoons parodying Mohammed. Apparently President Obama was prescient, at least in the case of the twelve dead Parisians, when he warned in 2012, "The future must not belong to those who slander the Prophet of Islam."
Our leaders regularly scoff at the notion of a "clash of civilizations" between the West and Islam, as Secretary of State John Kerry did when he said the attacks were "part of a larger confrontation, not between civilizations, no, but between civilization itself and those who are opposed to a civilized world." The jihadists know better, and like all enemies, they get a vote. They don't just want to brutally kill people in order to terrorize us into appeasement of their demands. They want to kill our fundamental principles.