I see that Ayaan Hirsi Ali is calling for individuals and news media organizations to respond to the Charlie Hebdo attack too, and I hope they follow her suggestions.[1]
A historical example I turn to about how to respond to grave national danger is that during the United States Civil War, the 1864 election occurred exactly on the expected schedule, and Abraham Lincoln was prepared to be voted out of office during the middle of the war. Of course in parliamentary systems elections do not occur at predictable intervals as they do in the United States constitutional system, but I've always thought that was a good example of how not to cave in to the temptation of self-benefit "for the sake of the country's stability" by delaying the election or something like that. Lincoln did invoke the power (a power granted by the Constitution from the beginning[2]) to suspend the right of habeas corpus during the War of Rebellion (as the Civil War was called by the Union at the time), but habeas corpus was restored as soon as the rebellion ceased.
We should cherish all of our freedoms all of the time and guard them zealously. We should exercise free speech to minimize the risk of future attacks like the attack in Paris, by openly disagreeing with the kind of thinking that leads to attacks like that.
[1] http://www.thedailybeast.com/articles/2015/01/08/ayaan-hirsi...