In the context of the Fort Dix hirabis, Victor Davis Hanson has some useful thoughts on the problem of completely uncontrolled immigration:

Once the United States accepts as a permanent condition the notion that several million illegal aliens can reside in perpetuity and under immunity from the law, then a sort of insidious message is established:

We in America will ask nothing of our immigrants-not legality, not English, not rudimentary knowledge of our history and values, and not real efforts at assimilation and Americanization.

So, the wannabe jihadist, here illegally, whether as in the Fort Dix case or as was true of a few of the 9/11 murderers