Here’s the wicked paradox about terrorism. Long-term responses do nothing about short-term dangers. Short-term reactions feed extremism over the long term.
There are no quick solutions and there may be no "solution" as we think of it. This is quite distressing for Americans in particular, I think. Pick your point in history as to when this dynamic began. This is one of those classic problems in human society for which the passage of time and the change of generations offer the only hope for "solutions."
That said, we need to think about becoming a resilient society and doing the right things in terms of security, etc. Paris, for example, compared to London, employs little camera surveillance. Many are troubled by the implications of constant government surveillance—I am—but the tradeoff has been judged worthwhile in the UK. There are many other actions to be taken along these lines. The Internet of Things and remote sensor technologies, for example, offer the ability to monitor indoor locations in real time. Such steps will not guarantee your safety. But they will improve outcomes on the margin.
I imagine all of the terrorists will be identified as Muslims. But that is not the more important identity in my mind. They are failed young humans—usually men—who blame others, including the West, for their lack of power. They take up arms and jihad to feel more powerful and to lash back. And that same motive will drive in part the response of Western governments and societies. We hate the feeling of powerlessness, and so we will do something—perhaps anything—to feel powerful and return fire.
But if I were still in government, I would not argue against that course of action. If your job is to protect the security of others, inaction is never the right answer—and so-called "long-term solutions" ring pretty hollow. We are not dealing with individuals who can be "nudged" into better behavior; this generation is lost. And kinetic action always offers the opportunity that you will scare some of their less-committed members and perhaps kill off some of their more talented leaders. But beware the politicians and experts who think any of this is easy, or that if we would only do this or that, we could fix the problem. That path leads to the dark side.