THE SHIELD OF ACHILLES: War, Peace, and the Course of History. By Philip Bobbitt. Knopf. 919 pp. $40

With seasonal regularity, a book appears that bids to be the one weighing down the briefcases carried in and out of government agencies and corporate headquarters. Invariably, the book contains a stark thesis, an easy fluency with history, and a set of prescriptions addressing future threats and opportunities. Philip Bobbitt's book might be seen as the latest such bid, but it's actually a considerably more nuanced, sophisticated, and in parts powerful avatar than this lineage often generates.

The spur to Bobbitt's book is a question that dominated international policy debates during the 1990s, especially in America: "Why is it so difficult for contemporary leaders to determine when to use force in international affairs?" Reflecting no doubt on the convulsive foreign-policy record of the Clinton era--with its characteristic swings between hyperactivity and quiescence--Bobbitt claims that difficulties crowd in because contemporary states find themselves in the midst of "a transitional period following the end of an epochal war." Caught in a strategic no-man's land, leaders are without any self-evident calculus by which to assess the costs of military actions.

Bobbitt is a professor of law at the University of Texas, a former National Security Council official, and the author of works on constitutional theory and nuclear strategy (an unusual combination of competences in the current academic division of labor). His new book, in marshaling this accumulated expertise, promises to offer a compass to point readers through the present political and moral morass. The great strength of this long, sometimes overinvolved, and occasionally preening study is its unswerving effort to stay focused on the modern state: to examine its origins, vicissitudes, and, more uncertainly, its possible futures. In Bobbitt's view, we are living through a deep change in the character of the state as we pass from the era of the nation-state to that of the "market-state."

The modern state--which began to emerge in the Italian city-states of the early Renaissance, was described most fulsomely and powerfully by Thomas Hobbes, and achieved its greatest practical form in the 20th century--is perhaps not the most glorious idea produced by the tradition of Western political thought, but it has proved the most well-traveled, resilient, and adaptable one. The modern state is at once the highest concentration of human lethal force and the most effective device so far invented for enabling what we judge to be a decent human existence. The only fate worse than having to live under the authority of a modern state is not being able to do so: woe to the stateless person, the sans papiers of the world.

As Bobbitt puts it, the modern state links together strategy and the constitutional order. Put more abstractly, the modern state represents the most enduring human effort to connect the two core dimensions of politics: power and value, the moral calculus by which to determine power's use. From an analytical viewpoint, if not from a practical one, this makes for an entity that is subject to profound instability. The precise nature of the relationship between power and value, and the particular balance between them at any given time, is a murky matter, requiring sharp observation and clearheaded judgment. It is a subject about which one can hope to be wiser in retrospect than in relation to the present or future--as Bobbitt's book bears out.

The book follows the path set down by some of the most trenchant analysts of the relation between war and the emergence of the modern state, above all the traditions of Otto Hintze and German staatsraison. Bobbitt shares some of these analysts' inclinations: a central causal role granted to conflict, a commitment to an implicitly evolutionary schema of state development, and a determination to relate the internal evolution of the modern state to the international order.

The core thought that drives the sprawling argument of The Shield of Achilles is roughly this: War is crucial in shaping the constitutional order of a state, and so the study of war is central to the history of the state; and the constitutional order of states, the study of their law, "must be at the center of the history of the society of states" in the international order. International law, Bobbitt claims, is derived from the constitutional order of particular states. By directing the causal chain in this way, he is able to maintain his focus on the state. He insists that "contemporary developments in limiting sovereignty are a consequence of the change in the constitutional order to a market-state"; they are not the direct effect of international developments, nor are they "imposed by international law, however flattering this may be to those who administer international institutions."

In the bulk of the book, Bobbitt identifies the nature of the current "transitional period" (which necessarily involves saying something about what went before and what might be expected to follow) and outlines the newly emerging form of the state and its effects upon the international order. We are blinking and disoriented, he argues, because we have just exited the "fifth epochal war in modern history," the period between 1914 and 1990, which he terms the "Long War." All five of these great wars concerned the constitutional order, the legitimate form the state should take, and out of each one emerged a particular state form: the princely and kingly state, the territorial state, the state-nation, the nation-state, and--from the Long War between fascism, communism, and parliamentarism--the emerging market-state.

Each successive form has augmented the state's responsibilities, to the point where today's nation-state is manifestly unable to fulfill its putative duties. Bobbitt offers a familiar catalogue of developments undermining the practical efficacy of the sovereign territorial state: the spreading recognition of universal human rights, the proliferation of weapons of mass destruction (which serve to alter the geography of defense by making physical borders ineffectual), and the increased transnational flows of environmental effects, populations, and capital.

Bobbitt is quite right to stress that today's difficulties afflict a particular form of the state--the nation-state--and not the state itself. Indeed, he argues, the evident fallibility and faltering of the nation-state already is provoking an adaptive response on the part of the state: the emergence and eventual consolidation of the market-state. In his description, this emerging state form is less fastidious about sovereignty. It finds ways to survive--and even to thrive upon--the caprice of international capital markets; it is willing to weaken institutions of representative democracy in favor of quasi-referenda such as opinion polls (the focus group replaces the debating chamber); and it is happy to shed welfare responsibilities. The market-state "exists to maximize the opportunities enjoyed by all members of society"--a far vaguer objective than the austere but tangible pledge of the Hobbesian state: security.

According to Bobbitt, leaders of the evolving market-state must decide whether to pursue what he terms entrepreneurial, managerial, or mercantile policies. These alternatives have given rise to three possible types of the market-state: the Washington, Berlin, and Tokyo models. The first, libertarian variant, tends toward minimal state intervention confined to infrastructure, and leaves the rest to private enterprise. The more consensual Tokyo model seeks to protect domestic industry and maintain sovereign control over capital. The Berlin model, social democratic in inclination, aspires to social and economic equality, employs the stakeholder idea, and gives more thought to future generations. Each model aims to maximize opportunity in a particular fashion, and each claims to be the definitive expression of the market-state--just as, according to Bobbitt, parliamentarism, fascism, and communism each once claimed to be the ultimate expression of the nation-state.

Given Bobbitt's views about the dynamics of historical change, it follows that the three models of the market-state will struggle for supremacy in the next epochal conflict. The form that survives will be the one best able to adapt to the challenges now confronting the modern state--challenges that are themselves residues of strategic innovations that helped win the Long War: weapons of mass destruction, the globalization of communications, and the international integration of trade and finance.

The concluding part of Bobbitt's study examines the emergence of the society of states and the international order. It traces in brief what he sees as moments of "epochal peace" that have set the terms of the international order--from the Treaty of Augsburg in 1555 to the "Peace of Paris" of 1990, which recognized a reunified Germany. Each state form has necessitated its own corresponding society of states, and so the rise of the market-state will transform the international order. The market-state is moving away from the territorial fixations of the nation-state, as it recognizes that many of the threats facing it are nonterritorial--for example, an attack on its computer or communications infrastructure. New strategies to deal with such threats often will make cooperative relations between states imperative, so the international society of states will come also to reflect a less territorial view of the state.

The weakening of territorial sovereignty should not, however, be interpreted as presaging the demise of the state. On the contrary, the fact that nonstate actors can now devastate modern states encourages a still closer merging, or even fusion, of law and strategy: War will appear increasingly as crime. Instead of relying on retaliatory and threat-based strategies, modern states must move toward defensive, vulnerability-based strategies. But it will remain a condition of success that these new strategies be devised and executed by a state.

The difficulties with Bobbitt's timely analysis lie in at least three directions. First, he dwells too little on the role of human belief and identification. Every state has taken as a strategic axiom that it can command people to die in its defense. Nationalism has proved one of the most powerful tools for sustaining such identification under modern conditions. As the market-state disburses itself and its responsibilities, it can expect lesser, and less intense, obligations from its members.

Second, for all its intellectual cosmopolitanism, The Shield of Achilles is, in its political tastes and hopes, a decidedly American book. Bobbitt declares that the United States--"culturally indifferent," militarily and economically mighty--is best placed to become the exemplary market-state. As so often before, it turns out that the purpose of all previous human history has been to yield up the American state of the particular moment. Library shelves testify that such perspectives do not weather very well.

Third, and most profound, there is a deep instability in Bobbitt's coupling of markets and states--of which he is certainly aware, but about which he is perhaps too insouciant. States and markets define the existing or strongly desired political habitat of most people on the planet today, but they do not constitute a harmonious pair. States seek to concert and concentrate intentions; markets seek to diffuse and disperse these intentions. Ever since the days of David Hume and Adam Smith, much of our politics has been bound up with the task of reconciling the authority that states claim with the utility that markets promise--a Sisyphean rather than a Herculean labor.