In Inspire, radical Yemeni-American preacher Anwar al-Awlaki explains that AQAP settled on attacking cargo planes because the jihadis’ foes would be faced with a dilemma once AQAP placed bombs on these planes. “You either spend billions of dollars to inspect each and every package in the world,” he wrote, “or you do nothing and we keep trying again.” Awlaki further explained, “The air freight is a multi-billion dollar industry. FedEx alone flies a fleet of 600 aircraft and ships an average of four million packages per day. It is a huge worldwide industry. For the trade between North America and Europe, air cargo is indispensable and to be able to force the West to install stringent security measures sufficient enough to stop our explosive devices would add a heavy economic burden to an already faltering economy.”

Inspire also explains that large-scale attacks, such as those of 9/11, are in its view no longer required to defeat the United States. “To bring down America we do not need to strike big,” it claims. “In such an environment of security phobia that is sweeping America, it is more feasible to stage smaller attacks that involve less players and less time to launch and thus we may circumvent the security barriers America worked so hard to erect.” (Al-Qaeda, however, has not abandoned catastrophic attacks entirely: its attempt to execute multiple Mumbai-style urban warfare attacks in Europe in late 2010 shows that these efforts continue.) The Foreman-Ali analogy is apt: al-Qaeda thinks it is turning the U.S.’s strength against it, envisioning the elevated security spending exhausting America and making it more vulnerable.

The fundamental problem with the U.S.’s system of homeland defense is that it has been structured in an expensive manner from top to bottom. One striking example is the U.S.’s hesitance to embrace a system of terrorist profiling (most notably in airports), which produces inefficiencies. As Sheldon Jacobson, a University of Illinois at Urbana-Champaign computer science professor who has studied aviation security since 1996, has noted: “Spending billions of dollars on screening the wrong people uses up finite resources. If we keep focusing on stopping terrorist tactics rather than stopping the terrorists themselves, the aviation security system will never reach an acceptable level of security.”

The problem is that if we simply slash our national security spending without making our system of defending against the terrorist threat more efficient and effective, we’ll end up less safe. Thus, a critical challenge the U.S. now faces is improving the efficacy of the system, even as it reduces its expenditures in an effort to escape from al-Qaeda’s rope-a-dope.