They say that the price of liberty is eternal vigilance. The carnage on the streets of Paris has brutally reminded Europeans of the fragility of the cocoon of safety and security in which they have become accustomed to living. There is a world of violence surrounding the continent; and both geography and the long intermingling of populations mean that Europe, unlike the United States, has no drawbridge option. If Europeans want to stay safe, they are going to have to take their defence and security a lot more seriously than they have in recent decades. [...]