The field of international security studies has long had an ethics problem: ethics is almost absent as a major tradition and concern within an otherwise diverse field that has long been at the heart of international relations. Against this background, this book is an important and valuable contribution. It is even more so as a work that aims to bring a fully developed ethics to one of the field’s most influential theoretical paradigms: the Copenhagen school’s theory of “securitization.” This school attempted to systematize three key tendencies in national security policy: the broadening of international security concerns beyond armed conflict to take in the environment, drugs, refugees, terrorism, and more; the resort to emergency politics and moral and legal rule-breaking in policy; and the increasing use of security rhetoric in public political discourse.

In answer, Copenhagen school theory ventured that there was no simple truth to security; rather, it was the product of performative “speech acts” that raise the status of some risk to an existential threat to the state such that it legitimizes the use of emergency language and measures. Yet the theory, even as it was extended and applied by hundreds of subsequent scholars, has skated around its ethical implications and dilemmas, relying merely on a preference for “desecuritization”—that is, a movement of an issue or risk back into a more routine, rule-bound structure of politics. Floyd rightly asserts that not only does this ignore the potential for “good” securitizations but it also fails to provide ethical guidance about the “circumstances when the move out of normal politics is morally permissible, and what considerations ought to inform the choices security measures used” (p. 2). By providing us with such a theory using the rigor associated with analytical moral philosophy, Floyd gives us a truly important contribution.

Via a generally fair engagement with literature in traditional and critical security studies and drawing on the methodologies of the just war tradition (JWT), Floyd structures the book so as to elucidate her security ethics, which she calls “just securitization.” This, she argues, should provide guidance as to when an issue may be securitized, how such a securitization should be conducted, and how and when securitization must be reversed. Her criteria for these decisions are nested within two categories analogous to the just war tradition’s jus ad bellum and jus in bello. A third, “just termination of securitization,” has no strict analogs in the JWT but might echo aspects of the more recent concern for postwar justice, peacebuilding, and reconstruction; more accurately, however, one might think of this category as a form of sociopolitical “demilitarization.”

The first criterion she calls “just initiation of securitization.” It has two key conditions: there must be “an objective existential threat to a referent object”—that is, a danger that threatens “the survival of the essential character of either a political or social order, an ecosystem, a nonhuman species, or individuals”— and the referent object (the thing to be made secure) must be “morally justifiable” These referent objects are morally justifiable if they “meet basic human needs…necessary components of human well-being.” They must meet three additional conditions: a “right intention for securitization…securitizing actors must be sincere in their attention to protect the referent object” (analogous to “just cause”); the expected good gained from securitization must be greater than the expected harm” (the double effect); and securitization must have a “reasonable chance of success” (pp. 19–20).

The second criterion, “just conduct in securitization,” holds that security measures should aim only to address the objective existential threat, they must be effective and cause the least overall harm possible, and they should “respect a limited number of relevant human rights” (pp. 20, 151–77). At this point, objections occur. Its first aim would limit mischievous forms of security politics and policy overreach, but why would securitization not respect the entire suite of human rights? They have been designed to be comprehensive and to dramatically limit exceptions, especially in the sphere of torture. International humanitarian law (IHL) already compromises the human rights of civilians caught in armed conflict and has been widely criticized. The resort to the double effect demonstrates that Floyd is not aiming to create a systemic form of structural security that might mitigate the armed conflict system, but one that might merely provide basic protections. This merely repeats the lacunae of the just war tradition and IHL, which create wide space for impunity.

My concerns here are compounded by the reluctance of the book to provide clear policy examples and guidance about what securitization would involve in terms of policy and security action, especially in cases outside armed conflict or the use of force. Nor is it ever clear whether it is only the state that would take such action or whether it would involve communities, and to what extent it might include democratic forms of deliberation and feedback. Although the book offers many interesting cases, they are often vague when it comes to what a securitized policy response is and where moral thresholds lie.

The third criterion, “just termination of securitization,” argues that de-securitization must occur when threats have been neutralized or, in the case of an unjust securitization, immediately. Floyd argues that these securitizations should be publicly declared, and security language and measures should be terminated with immediate effect. To “avoid renewed or reactionary securitization, de-securitizing actors should undertake context specific restorative measures” (p. 21).

Later chapters work through and justify her criteria at some length, in analysis that is thorough and supported with ample moral good sense. Her treatment also results in some interesting twists in critical security studies. Floyd agrees that securitization is a speech act but that insecurity is also real, which should be a source of moral constraint. She also provides generally compelling moral grounds for the expansion of the security agenda to take on new concerns and referent objects and exclude others. We ought to welcome such normative clarity.

Such a short review cannot grapple with the book’s overall richness, so let me conclude with three concerns about its argument. Like much ethics, it veers toward moral absolutism built on a prescriptive moral ontology. I have no objection to this per se, but such ontologies should come under scrutiny. Unlike the Copenhagen school, whose ontology is statist and involves a dismissal of human security, Floyd grounds her case for “just referent objects”—social and political orders, ecosystems, and human individuals—in their ability to meet “basic human needs.” She fleshes this out by arguing that “human well-being” is an intrinsic good that must be secured. So far so good. However, in the introduction she dismisses “world” and “cosmopolitan” security theories because their commitment to rethinking “security as a state of being” dilutes the clarity involved in locating security in securitization and the state. What she dismisses with one hand, she brings back with the other. She was right to bring it back and should have seized the opportunity to decisively rethink the Copenhagen school’s statism, which fails the reality of our complex, enmeshed, and interdependent world.

This leads to another weakness in the book’s thesis. Floyd holds that human beings are intrinsically rather than instrumentally valuable and that ecosystems and nonhuman species have value only when they deliver ecosystem services to human communities. Although the biosphere provides enormous ecosystem services, amounting to hundreds of trillions of dollars annually, she misses the opportunity to develop a valuation of ecosystems and the biosphere in and of themselves. Doing so would involve a security response that grapples with the systemic and complex nature of the processes that generate insecurity today. This is a significant lacuna in the work. Rather than grapple with the enormous complexity of climate governance and fossil-fueled industrialization, the book discusses a bizarre dilemma as to whether a national leader who prevents climate mitigation can be killed. (She concludes not.) Although intriguing as a normative discussion of possible justifications for ecoterrorism, such examples cannot provide answers to how we can secure the Anthropocene biosphere in the face of the systemic challenges of climate change.

Whatever its flaws, this is an important work. Any person interested in the ethical dilemmas inherent in international security, and especially those working with Copenhagen school thinking, should find this book invaluable. I hope we are thinking and arguing with it for a long time to come.