Five years after 9/11, are we any safer? In the lead essay of this month’s Cato Unbound, Ohio State University political scientist John Mueller offers a set of provocative reflections on what that question might mean. Along the way, Mueller argues that the terrorist threat to American lives is overblown, and that the attempt to protect ourselves against any possible attack is impossible, and a waste of taxpayer money. “It would seem to make more sense,” Mueller writes, “to substantially abandon the quixotic policy of seeking to make everything (or even a lot of stuff) safe, and then use the money saved to repair any terrorist damage and to compensate any victims.”

Clark Kent Ervin, Director of the Homeland Security Initiative at the Aspen Institute, and author of Open Target: Where America is Vulnerable to Attack counts himself among those who “strongly disagrees with both [John Mueller’s] premises and his conclusions.” Ervin stresses al Qaeda’s repeated intention to again attack the United States, and the alleged proliferation of terror cells in the United States and abroad. Ervin takes issue with what he calls Mueller’s “argumentum ad statisticum”–comparing terrorist murder to accidental death–and maintains that in a context of uncertainty about future attacks, “I’d rather err on the side of the believers. The downside of being wrong is so much smaller!”

Veronique de Rugy, resident fellow at the American Enterprise Institute, argues that the $271.5 billion devoted by the federal government to homeland security since 9/11 has not been well spent. “Not only are we over-investing in homeland security,” de Rugy argues, “but most times we spend too much money in the wrong way and on the wrong things.” The consequence is that we are no safer. “Bad security is often worse than no security at all,” de Rugy writes. “By trying, and failing, to make ourselves more secure, we make ourselves less secure.”

Timothy Naftali, author of Blind Spot: The Secret History of American Counterterrorism, argues that “the threat is getting wider without being deeper,” with new terror recruits failing to form “the kind of militaristic groups that would be needed to mount a serious military threat to the U.S. mainland.” Naftali argues that though the Bush administration deserves credit for weakening Al Qaeda, it has otherwise been “largely incompetent” in denying terrorists sanctuaries, and discouraging recruits to violent extremism. The main danger, Naftali contends, is that a terror group acquires a loose nuke, and the U.S. needs to attend more to this specific problem.