I am still a bit surprised when I hear this question: How many terrorists has the Department of Homeland Security caught? Probably for most employees at DHS, it’s an odd question. Which is why it’s a critical public relations matter. Most Americans still don’t understand the mission of DHS.

Why is it an odd question? It’s not DHS’s job to catch terrorists, per se.

Yes, DHS has as its mission the goal of preventing another terrorist attack on American soil. So catching terrorists would seem like an obvious part of that. Except it’s not. Prevention is the key word. The job of the folks at DHS is not so much to catch terrorists but to prevent them from successfully implementing a terrorist operation. Catching and preventing may at times overlap, but more often than not, for the majority of cases, they do not.

The FBI is the primary agency responsible for investigating and bringing individual terrorists to justice. The job at DHS is to implement a wide variety of tactics and strategies to prevent terrorists from ever setting foot on U.S. soil or being able to smuggle in the materials and resources they need for an operation. If you consider the nearly infinite ways in which terrorist groups might achieve their aims, you can see that this is a daunting challenge. And, unfortunately, when DHS is successful, most Americans never know it. The good work of DHS agents and employees goes largely unheralded.

During a trip to the border recently, as part of a group to review border security operations with the federal government, somebody asked this question, heard often in the halls of DHS and from the media during news conferences: Are you catching any terrorists?

The implication of the question – usually the questioner already knows the answer – is that the failure to catch members of al Qaeda during the fingerprinting processes at the border, or during Border Patrol operations along the southwest land border, or during the student visa process, or during the airport screening process … the implication is that the tactics implemented by DHS are obviously failing. No terrorists.

It is important to remember, however, that we usually won’t know if the efforts are successful – at least from the perspective of stopping the next al Qaeda operative. It should be remembered that most of the September 11th terrorists who entered the United States did so by exploiting our immigration system. For example, Hani Hanjour, one of the men who helped crash a 757 into the Pentagon, entered America allegedly as a foreign student. He applied for and received his student visa, but he never set foot on the school at which he was supposedly studying. In fact, nobody ever heard from him again until that fateful morning of September 11, 2001.

Had the DHS student visa program been in place at the time, Hanjour’s failure to show up at the school for which he was given a visa would have resulted in an alert being issued to US Immigrations and Customs Enforcement. ICE would have then investigated the matter. Had they run down Hanjour, he would have been deported.

And he would never have been tagged as a “terrorist.” He would only have been an individual who was caught exploiting the immigration system – like millions of others who do the same.

So, yes, it’s true that few terrorists are “caught” by DHS. It’s also true that few terrorists who are caught will likely ever be known.

Chris Battle founded Security Debrief as a forum for the homeland security community to discuss pressing issues and current debates in national security, counter-terrorism and law enforcement. After a long fight against kidney cancer, Chris passed in August 2013. Read More