It is through our own actions, or lack of action rather, that we have allowed this situation to happen. To blame the jihadists alone, is to avoid addressing our own inadequacies, and to repeat the cycle which ultimately leads to this point.
If the issue was as simple as shutting out the immigrants from coming in, then there shouldn't be a problem. We would do this and we would be fine. But several of the causes that led to this scenario would go unaddressed, such as the impulse of Western people to "help" people of other cultural backgrounds (apparently by bombing them and then by literally allowing themselves to be fucked over for it as part of the guilt trip), and the tendency of our politicians to get involved with foreign issues that should not concern them in any way whatsoever, among many other things.
These all result from the "globalist" mind-set that has developed and is continuing to develop among the Western people, and it is causing havoc all over the world, now including our own nations. No longer do they believe that they are inhabitants of the land that they were born into, but of the world, and that the entire world ought to be their playground, despite lacking even the most basic understanding of 90% of it.