The Preventive State

I am a Humean being. David Hume is my favorite philosopher, and it’s not even close. The way Hume set up the core problem of political institutions is brilliant:

In all governments, there is a perpetual intestine struggle, open or secret, between authority and liberty; and neither of them can ever absolutely prevail in the contest. A great sacrifice of liberty must necessarily be made in every government; and it is impossible to maintain perfect security, without great restraints: And, on the other hand, authority loses its proper force, whenever it transgresses the bounds of moderation, and encroaches too far upon the liberty of the subject. (David Hume, 1994, Essays: Moral, Political, and Literary, edited by E. F. Miller, Liberty Fund, 40)

Hume’s argument is that all humans know the right way to act (a nod to John Locke), but that many people nonetheless act badly, and will always act badly unless something like a state forces them to act properly (a nod to Thomas Hobbes). Humans are “seduced” by present, frivolous temptations to cheat or act badly, even though we all know it would be better to act to preserve order and propriety. This tendency is “incurable,” leaving humans “to palliate what they cannot cure” (38).

The useful thing about Hume’s realism, which some see as pessimism, is that there will always be a tension between authority and liberty. There is no perfect solution, and over time the political dialectic is very likely to be excessively reactant to one or the other pole of the struggle. 

It is clear from the subtitle of the book considered here—The Challenge of Preventing Serious Harms While Preserving Essential Liberties—that the same dilemma is the starting point for Alan Dershowitz. In a way, it’s analogous to the problem laid out in the Tom Cruise potboiler movie, Minority Report (2002). Set in Washington, D.C., in the year 2054, Minority Report follows Chief John Anderton, who works for “PreCrime,” a specialized police unit that uses three psychic beings known as “Precogs” to predict murders before they occur. By relying on their visions, PreCrime officers arrest individuals before they commit crimes, eliminating murder from the city.

Anderton is a firm believer in the system—until the Precogs predict that he will commit a murder in 36 hours. On the run, he tries to prove his innocence by uncovering the flaws in the system. He discovers the concept of a “minority report”: an alternative prediction that differs from the majority judgement, suggesting that the future is not fixed, and that outcomes that are likely are not certain.

In criminal trials in the U.S., the standard for being detained and punished generally has two parts. First, acts and not plans are crimes; second, the level of certainty has to be “beyond a reasonable doubt,” which echoes the “likely but not certain” framing. However, as the potential for destructive harm has increased, the tendency to try to anticipate future malign actions has become a main focus of civil authorities. In Preventive State, Dershowitz explores the growing tension between civil liberties and anticipating violent action. Dershowitz contends that this transformation—from a reactive to a preventive state—poses profound legal and moral challenges that democratic societies must confront openly and transparently.

He begins by discussing the inevitability and in some cases the necessity of preventive measures in the age of terrorism, biological warfare, and cyberattacks. He acknowledges that democracies cannot afford to wait until catastrophic acts occur before intervening. However, he warns that preventive governance is inherently prone to abuses of power, especially when it operates in secrecy or without clear legal boundaries.

To address this dilemma, Dershowitz proposes a framework of “open prevention”—a legal and regulated system where preventive actions are debated, legislated, and subjected to oversight. He explores controversial practices such as preventive detention, targeted surveillance, torture warrants (a concept he controversially defended earlier), and preemptive strikes in military contexts. Rather than banning such practices outright, he urges democratic societies to confront them directly and develop explicit legal rules governing their use.

Dershowitz draws on examples from American history and other liberal democracies to show how preventive policies have often been implemented during periods of fear—typically through executive overreach or emergency declarations. He critiques the post-9/11 expansion of surveillance under the Patriot Act, the use of indefinite detention at Guantanamo Bay, and the reliance on executive discretion in authorizing drone strikes and rendition.

A core concern is the erosion of due process and civil liberties in the name of national security. Dershowitz emphasizes that secrecy, rather than prevention itself, is the primary danger. For example, he argues that if practices like torture or targeted killings are to be employed, they must be authorized through public debate, legal accountability, and judicial oversight. He believes this is the only way to preserve democratic legitimacy and protect against arbitrary or discriminatory application.

In conclusion, Dershowitz does not reject the preventive state outright but calls for transparency, accountability, and legal clarity in how preventive powers are exercised. He advocates for a new jurisprudence that balances liberty with security in a principled and openly contested manner.

The book has some successes, and some aspects that are less successful, as I see it. On the plus side, Dershowitz confronts uncomfortable legal and moral questions—such as torture or targeted killings—rather than ignoring or sanitizing them. Also, while he defends civil liberties, he realistically acknowledges that modern threats require preventive action. And overall the book is clear and well-written. 

The book is less successful, at least for me, when it countenances the claim that there are some circumstances where torture or preventive detention might be justified, or even required. A nice theoretical parsing of degrees of risk and the potential for harm is likely to run afoul of the zeal by the authorities to use such tools in far more circumstances than were envisioned when torture was (contingently) authorized. Dershowitz’s main claim is likely to be controversial: either torture should be outlawed completely, or else its use should be “transparent” (93–94); his justification is that the worst path is to pretend torture is outlawed while allowing it to occur in secrecy “when necessary.” This faith in transparency may be naïve: legalizing controversial practices may make them more routine rather than more accountable.

Dershowitz spends a number of pages at different points of the book posing hypothetical questions, in the manner of the law pedagogue that he is. The problem with hypothetical cases—you know for certain that this person knows the location of a nuclear weapon in Manhattan, and it will explode in 2 hours; would you torture them?—is that such “edge cases” can make for bad policy. Of course, Dershowitz is a famous civil libertarian, in the John Stuart Mill tradition. Mill famously said: 

Strange it is, that men should admit the validity of the arguments for free discussion, but object to their being “pushed to an extreme”; not seeing that unless the reasons are good for an extreme case, they are not good for any case. (J. S. Mill, 1991, On Liberty and Other Essays, Oxford University Press, 26.)

I’m not sure that’s right, at least not when it comes to criminal procedure. We must recognize that the majority of cases, the majority of the time, must be treated with deference to the rights even of those we detest and do not trust. Of course, that means that there will be some successful terrorist attacks and violent events, things that might have been prevented with more concentrated authority and a sacrifice of liberty. Dershowitz does us the favor, and deals us the stinging insult, of forcing this consideration to be made intentionally, and without hypocrisy. That is uncomfortable, but he persuaded me it is increasingly necessary.