Enlightenment Now: The Case for Reason, Science, Humanism, and Progress

The legal scholars Oona Hathaway and Scott Shapiro argue that it’s the outlawry of war that deserves much of the credit for the Long Peace. The idea that nations should agree to make war illegal was proposed by Kant in 1795. It was first agreed upon in the much-ridiculed 1928 Pact of Paris, also known as the Kellogg-Briand pact, but really became effective only with the founding of the United Nations in 1945. Since then, the conquest taboo has occasionally been enforced with a military response, such as when an international coalition reversed Iraq’s conquest of Kuwait in 1990–91. More often the prohibition has functioned as a norm—“War is something that civilized nations just don’t do”—backed by economic sanctions and symbolic punishments. Those penalties are effective to the extent that nations value their standing in the international community—a reminder of why we should cherish and strengthen that community in the face of threats from populist nationalism today.²⁴

To be sure, the norm is sometimes honored in the breach, most recently in 2014, when Russia annexed Crimea. This would seem to confirm the cynical view that until we have a world government, international norms are toothless and will be flouted with impunity. Hathaway and Shapiro reply that laws within a country are broken, too, from parking violations to homicides, yet an imperfectly enforced law is better than no rule of law at all. The century before the Paris Peace Pact, they calculate, saw the equivalent of eleven Crimea-sized annexations a year, most of which stuck. But virtually every acre of land that was conquered after 1928 has been returned to the state that lost it. Frank Kellogg and Aristide Briand (the US secretary of state and the French foreign minister) may deserve the last laugh.

Hathaway and Shapiro point out that the outlawry of interstate war had a downside. As European empires vacated the colonial territories they had conquered, they often left behind weak states with fuzzy borders and no single recognized successor to govern them. The states often fell into civil war and intercommunal violence. Under the new international order, they were no longer legitimate targets of conquest by more effective powers, and hung on in semi-anarchy for years or decades.

The decline of interstate war was still a magnificent example of progress. Civil wars kill fewer people than interstate wars, and since the late 1980s civil wars have declined as well.²⁵ When the Cold War ended, the great powers became less interested in who won a civil war than in how to end it, and they supported UN peacekeeping forces and other international posses which inserted themselves between belligerents and, more often than not, really did keep the peace.²⁶ Also, as countries get richer, they become less vulnerable to civil war. Their governments can afford to provide services like health care, education, and policing and thus outcompete rebels for the allegiance of their citizens, and they can regain control of the frontier regions that warlords, mafias, and guerrillas (often the same people) stake out.²⁷ And since many wars are ignited by the mutual fear that unless a country attacks preemptively it will be annihilated by a preemptive attack (the game-theoretic scenario called a security dilemma or Hobbesian trap), the alighting of peace in a neighborhood, whatever its first cause, can be self-reinforcing. (Conversely, war can be contagious.)²⁸ That helps explain the shrinking geography of war, with most regions of the globe at peace.

Together with ideas and policies that reduce the incidence of war, there has been a change in values. The pacifying forces we have seen so far are, in a sense, technological: they are means by which the odds can be tilted in favor of peace if it’s peace that people want. At least since the folk-song-and-Woodstock ’60s, the idea that peace is inherently worthy has become second nature to Westerners. When military interventions have been launched they have been rationalized as regrettable but necessary measures to prevent greater violence. But not so long ago it was war that was considered worthy. War was glorious, thrilling, spiritual, manly, noble, heroic, altruistic—a cleansing purgative for the effeminacy, selfishness, consumerism, and hedonism of decadent bourgeois society.²⁹