At noon Monday, Professors John Mueller and Mark Stewart will be here to discuss their new book: Terror Security and Money: Balancing the Risks, Benefits and Costs of Homeland Security. Register here.

The question in this post’s title is the book’s. It quantifies Mueller’s skepticism about the utility of homeland security spending with cost-benefit analysis, which is Stewart’s specialty. They use this analysis, which is employed by various federal agencies as part of the regulatory review process, to show that little of what the Department of Homeland Security does is a good investment. That is, the bulk of its activities cost more—measured in lives or dollars— than they save. In the conclusion, where you find most of the book’s political science, Mueller and Stewart discuss why DHS avoids this sort of analysis—neither it nor its political advocates have much reason to advertise its wastefulness—and why that should change.

Alan Cohn, Deputy Assistant Secretary for Policy at DHS, has boldly agreed to join the proceeding. DHS rules prohibit him from commenting directly on the book, but he will presumably defend his department and discuss how it considers policies’ cost and benefits, or what it calls risk management.

That all sounds very wonky, I know. Here is why the book and forum should interest those not particularly concerned with homeland security or risk analysis: the book calls a bluff. One of the great myths about U.S. national security is that it aims to maximize safety. Almost everyone speaks about security as if this were so.

The truth is instead that every security policy, indeed every government policy, is a choice among risks. Most policies aim to mitigate risk in some way and by expending resources expose us to other risks. Our policy preferences and ideologies are largely beliefs about which risks to combat socially and which to leave to individuals, or least how much attention we should pay to competing risks. Our society, it turns out, is willing to pay far more to save lives from terrorism than most other dangers. That is, we value lives lost from it far more highly than those lost in other ways. We trade small gains in protection from terrorists for substantial losses in our ability to combat other troubles.

By asking what U.S. homeland security would look like it if truly aimed to maximize safety against all dangers, Mueller and Stewart’s book makes plain that we have chosen to do otherwise. People that disagree about the merit of that choice should agree at least that it is one we should make openly. Democracies make better choices when they perceive them.