The universality was important in an increasingly secular age when a dwindling number of people were prepared to die simply for God, and an even-more rapidly dwindling minority were prepared to lay down their lives for their King, even assuming that they still had one. Armies now consisted increasingly of volunteers or conscripts who needed a motivation that would inspire them all, regardless of class or creed. As the traditional foci of loyalty faded, they were replaced by the far more powerful concepts that were to fuel the great national wars of the nineteenth and twentieth centuries, in which young men were to die and kill for their "country" or "Fatherland"; though when possible, as we have seen, "God" and "King" were bracketed with it in an all-embracing trinity.

BUT BY the twentieth century we are entering a third, or post-Westphalian era: that of what might be termed "Enlightenment Wars." The savants of the eighteenth-century Enlightenment had argued that war, so far from being an inevitable if not positively desirable element in human affairs, was an unnecessary evil created by the self-interest of monarchs and their attendant aristocrats who then ruled the peoples of Europe. Wars were thus justifiable, they argued, only if they were fought to liberate peoples from these oppressive regimes, whether they were homegrown or foreign-imposed. The first such war for what would now be termed "regime change" was that commenced by the French revolutionary government in response to the Allied invasion of 1793, when the French invaded their neighbors to liberate them from monarchical oppression; a rationale that inspired the armies of Napoleon Bonaparte to carry the flag of Liberty, Equality and Fraternity throughout a rather ungrateful Europe. This set the pattern for "wars of liberation" fought during the nineteenth century to free the Greeks, the Italians and the peoples of the Balkan peninsula from oppressive Austrian or Ottoman rule. It was a concept that received its full epiphany in 1917, when President Woodrow Wilson took the United States into the First World War, proclaiming that America would fight not, like the European powers, simply for her own national interest but "for democracy, for the right of those who submit to authority to have a voice in their own governments, for the rights and liberties of small nations, for a universal dominion of right by such a concert of free peoples as shall bring peace and safety to all nations and make the world itself free." The conflict between Pale Ebenezer and Battling Bill now seemed resolved: the justification for going to war was to bring war itself to an end.

But although the democracies triumphed in 1918, their peoples still proved very reluctant to fight Enlightenment Wars. The Americans dissociated themselves from Wilson's "concert of free peoples," the League of Nations, with all the uncomfortable obligations that membership would have involved. The French and British refused even to contemplate war against Japan in 1931 or Italy in 1935 when those states invaded and subjugated peaceful peoples in defiance of their international obligations. When France and Britain did eventually go to war in 1939, their immediate justifications were in principle purely "Westphalian": to fulfill treaty obligations and maintain a balance of power; but fundamentally their peoples agreed to fight because they realized that their "countries" were now in danger. The United States and the Soviet Union remained aloof even longer, and entered the war only when they were themselves physically attacked. Whatever the rhetoric of their leaders, the vast majority of the people who actually fought those wars did not do so for democracy or fascism or communism. They simply fought, as they had a generation earlier, for their "countries"; the Americans as much as everyone else.

Nevertheless, whether or not the American people believed that they had been fighting an Enlightenment War for a better world, at the end of it President Roosevelt was better placed than had been any of his predecessors to insist upon a truly Enlightenment peace; that is, the establishment of a community of self-governing democracies, by definition peace-loving, who would go to war only to restore the international order if it were threatened by a "rogue state." Five years later, when North Korea invaded its southern neighbor, the United Nations actually did so. National armies then fought, however notionally, under a United Nations flag. But it was still assumed that such wars would be fought between states. Their object was to preserve an inter-national order in which the only serious actors would be states who still enjoyed, as Max Weber had put it, a "monopoly on violence." To that extent the system was still "Westphalian": peace would be kept and order maintained by interstate agreements. Those who fought these Enlightenment Wars, if called upon to do so, would do so because their State so ordered, albeit in a higher cause. So far as the armed forces themselves were concerned, they were still fighting for their country.

THEN CAME the appalling atrocity of 9/11. This foreshadowed an entirely new era; one in which states could be threatened, and international order disrupted on a major scale, by "nonstate actors." It was no longer states as such whose integrity was now threatened, in whose defense they might invoke traditional patriotism: it was the whole structure of international society, on whose effective functioning the well-being of all its members depended. Nonstate "terrorists" of a kind had always existed in the shape of domestic rebel groups or extranational pirates, but their impact had hitherto been marginal and local, posing problems mainly of internal order. Now, in an interdependent world, their activities could have global consequences: with the availability of nuclear weapons, they threatened lethality on a scale comparable to that of a major war. In the United States this new situation has been termed "The War on Terror," but even if there is no such all-embracing conflict, there are certainly specific wars being fought in which people are killing and being killed. These deserve to rank as "Enlightenment Wars," but of a kind rather different from their predecessors.

Hitherto, as we have seen, "Enlightenment Wars" have been fought by states to preserve or restore peaceful order among themselves. Today they have to be fought, not only against nonstate actors, but on behalf of nonstate actors: that is, of a global, interdependent, transnational civil society that transcends states, but on whose effective functioning the entire world depends. In this perspective 9/11 must be seen not as an act of "war" but as a global "breach of the peace." Its perpetrators, whatever they may think of themselves, should be regarded not as "belligerents" but as transnational criminals against whom it may be necessary to deploy-as in domestic police operations it may be necessary to deploy-limited and strictly controlled armed force in order to preserve the global order that they are seeking to destroy.

For lack of any alternative, such armed force can still be provided only by existing states. States must now be not only the guardians and protectors of their own national interests, but also trustees for the security of that transnational order on which the well-being of their citizens ultimately depends. It is their responsibility as trustees of the global community that now provides a jus ad bellum for intervention in regions where events pose an evident danger to that community, giving their armed forces a license to kill and expose themselves to the risk of being killed.

The trouble is, the motivation of those forces is still likely to be "Westphalian." That is, they still enlist to fight for their country against its enemies, not act as international policemen on behalf of a global community. They still instinctively think in terms of defeating an enemy and proclaiming a victory, rather than of bringing criminals to justice and maintaining a just order. As Secretary of State Condoleezza Rice once put it, they are not there just to escort kids to school. But if these Enlightenment Wars are to be fought effectively, it can only be by military forces that possess the restraint and humanity of good policemen who take escorting kids to school as a matter of course and regard killing, though it may occasionally be necessary, as a sign of ultimate failure; a lesson that the forces committed to Iraq have had, rather painfully, to learn.

It is not surprising that states, even the most "enlightened," find this a problem. It still remains easier to motivate young people to fight and die for their "country," antiquated though that appeal may be, than to act as policemen for a "global society"-a concept with which many of them may have little sympathy anyhow-under conditions of great discomfort and danger a very long way from home, where they are confronting adversaries ready and willing both to kill and to die in the name of their own God. To do so demands from the military a new kind of professionalism, at once dispassionate and humane, rather different from the Westphalian readiness to kill and to die in the name of their country against a named and evident enemy.