n the final decade of the century that has just ended, three of the most distinguished political philosophers of the time turned their attention to the international scene. In the early nineties, each had published what could be seen as a culminating statement of their reflections on the internal life of Western liberal democracies: Jürgen Habermas’s Faktizität und Geltung (1992), John Rawls’s Political Liberalism (1993), and Norberto Bobbio’s Destra e Sinistra (1994). There followed, focusing now on external relations between states, Habermas’s ‘Kant’s Idea of Perpetual Peace: at Two Hundred Years’ Historical Remove’ (1995) and ‘The Postnational Constellation’ (1998), and Rawls’s Law of Peoples (1999). Bobbio, who had started thinking about international relations much earlier, and anticipated many of their concerns in ‘Democracy and the International System’ (1989), produced more punctual interventions in these years, each arousing major intellectual debates.footnote1 The apparent alteration in attention of Rawls and Habermas, previously often reproached with lack of concern for global issues, was by contrast striking. In the background to a new set of preoccupations, on the part of all three thinkers, stretched the frieze of world history, as the end of the Cold War brought not pacification of relations between states, but military engagements of a frequency not seen since the sixties, in the Gulf, the Balkans, the Hindu Kush and Mesopotamia. Each philosopher sought to offer proposals appropriate to the time.

Of the three, it was Rawls who offered the most systematic outline of a desirable international order. The Law of Peoples extends the modelling devices of A Theory of Justice from a national to a global plane. How is international justice to be realized? Rawls argues that we should imagine an ‘original position’ for the various peoples of the earth parallel to that for individuals within a nation-state. In it, these collective actors choose the ideal conditions of justice from behind a veil of ignorance concealing their own size, resources or strength within the society of nations. The result, he argues, would be a ‘law of peoples’ comparable to the contract between citizens in a modern constitutional state. But whereas the latter is specifically a design for liberal democracies, the scope of the former extends beyond them to societies that cannot be called liberal, yet are orderly and decent, if more hierarchical. The principles of global justice that should govern democratic and decent peoples alike correspond by and large to existing rules of international law, and the Charter of the United Nations, but with two critical corollaries.

On the one hand, the Law of Peoples—so deduced from an original position—authorizes military intervention to protect human rights in states that are neither decent nor liberal, whose conduct brands them as outlaws within the society of nations. Regardless of clauses to the contrary in the un Charter, these may be attacked on the grounds of their domestic policies, even if they present no threat to the comity of democratic nations. On the other hand, the Law of Peoples involves no obligation to economic redistribution between states comparable to the requirements of a justice within democratic societies. The Difference Principle, Rawls explains, does not apply between peoples, since the disparities in their wealth are due not to inequality of resources, but principally to contrasts in culture. Each society is essentially responsible for its own economic fate. Better-off peoples have a duty of assistance to those that are historically more burdened by their culture, but this does not extend beyond helping them achieve the sufficiencies needed for a decent hierarchical order. A legal empyreum that conformed to these rules would have every chance of extending the peace that has reigned for more than a century between the world’s democracies to all corners of the earth. The Law of Peoples, inspired by the long experience of this silence of arms among liberal societies, configures a ‘realistic utopia’.

Rawls explains at the outset of The Law of Peoples that the basic intention of his work was to offer a contemporary version of Kant’s For a Perpetual Peace: A Philosophical Sketch of 1795. Habermas, proceeding from the same inspiration, sought more explicitly to update Kant, reviewing the posthumous fortunes of his scheme on the occasion of its bicentenary and, where necessary, adjusting it to present conditions. War could be abolished, Kant had believed, by the gradual emergence of a federation of republics in Europe, whose peoples would have none of the deadly impulses that drove absolute monarchs continually into battle with each other at the expense of their subjects—the drive for glory or power. Rather, interwoven by trade and enlightened by the exercise of reason, they would naturally banish an activity so destructive of their own lives and happiness. For well over a century, Habermas observes, history rebuffed this prospect. Democratic peoples showed they could be just as bellicose as autocratic princes. Instead of peace-giving trade, there came industrial revolution and class struggle, splitting rather than uniting society. The public sphere became prey to distortion and manipulation with the arrival of modern media. Yet since the close of the Second World War, Kant’s vision has come to life again, as his premises have been fulfilled in altered conditions. Statistical research confirms that democracies do not war with each other. Within the oecd, nations have become economically interdependent. The welfare state has pacified class antagonisms. ngos and global summits on population or the environment show that an international public sphere is taking shape.

But if Kant’s diagnostic has today been vindicated, his institutional scheme for a perpetual peace has proved wanting. For a mere fœdus pacificum—conceived by Kant on the model of a treaty between states, from which the partners could voluntarily withdraw—was insufficiently binding. A truly cosmopolitan order required force of law, not mere diplomatic consent. The un Charter, in banning aggressive wars and authorizing measures of collective security to protect peace, and the un Declaration of Human Rights, laid some of the legal bases for one. But in continuing—inconsistently—to proclaim national sovereignty inviolable, the Charter had not advanced decisively beyond Kant’s original conception. The transformative step still to be taken was for cosmopolitan law to bypass the nation-state and confer justiciable rights on individuals, to which they could appeal against the state. Such a legal order required force: an armed capacity to override, where necessary, the out-dated prerogatives of national sovereignty. The Security Council was an imperfect instrument of this imperative, since its composition was open to question and its actions were not always even-handed. It would be better if it were closer in model to the Council of Ministers in the European Union, but—in this unlike the latter—with a military force under its command. Nevertheless, the Gulf War was evidence that the un was moving in the right direction. The present age should be seen as one of transition between international law of a traditional kind, regulating relations between states, and a cosmopolitan law establishing individuals as the subjects of universally enforceable rights.