The famous Chinese General Sun-Tzu wrote an acclaimed book thousands of years ago called The Art of War. In this book, he writes that "all warfare is based on deception." In the war on terror, things are no different. It is common knowledge that terrorist operatives will conduct weeks, months or even years of intelligence gathering of an intended target. It is our mission to interrupt, prevent and stop these attacks from occurring. The aviation mission is therefore two-fold. One, create a presence; coupled with patrol and specialized units, a presence that deters them from a particular target. Be highly visible and make noise. The purpose is high visibility. Two, gather intelligence. Look for suspicious cars, look for suspicious people. Is that really a county work crew working on the street in front of the chemical plant? Find out! Work with all units within your agency to construct a focused and comprehensive counter-terrorism mission rather than just choosing random locations for directed patrols. The whole effort will be much more effective with cooperation and teamwork.
Although difficult to measure empirically, an agency can see at least some of the results of their efforts. One, the lack of attacks certainly means we are doing something right. Two, intelligence received from terrorist organizations might hint at the success of a strategy. In 2004, a terrorist operative had been assigned to blow up the Brooklyn Bridge in New York City. During his pre-mission surveillance, he constantly saw NYPD helicopters, harbor boats, patrol units and the heavily armed Emergency Services Unit performing patrols on the bridge. Obviously, this presence would have a severe impact on the planned attack and he sent an e-mail back to his superiors: "I will be unable to continue my assigned mission because the weather is too hot." The weather, of course, was the police presence.