What's left to say about war? The phenomenon has been amply addressed by hexameter-spouting pre-literates, Confucian generals, shell-shocked poets, writers' workshop jarheads, and untold numbers of eminently qualified commentators in between. Amid all that rhapsodizing, lamenting, codifying, strategizing, speculating, and eulogizing is the uncomfortable truth that nobody has yet figured out how to put an end to it. But, hey, didn't the threat of war reach its apogee in the late twentieth century, when the cocked and loaded ICBMs of two competing superpowers threatened to scorch or choke all human life from the planet? Now that the Cold War is over, aren't we dealing with a new type of conflict with much lower stakes-the occasional overthrow of some belligerent Third World dictator, the pacifying of ethnic enmity in the usual hot spots, the killing or capturing of a few politically disenfranchised radicals with secessionist or Islamist agendas? We're making progress. So haven't we heard enough already?
Well, no actually. As Gwynne Dyer makes clear in the new edition of his book, War, the world is facing "three great changes . . . that could tip the international system back into the old anarchy: the environmental challenge of climate change, the political challenge of the rise of new great powers, and the technological challenge of nuclear proliferation." As the global population surges past sustainable levels, as calamitous disruptions to the biosphere make themselves felt more acutely, as ascendant nations vie with one another for economic and military supremacy, it's possible that humanity will be pressured into its old pattern of war-making, and this time, use all of the weapons at its disposal. It may be, as Dyer points out, that we're simply enjoying ""the Indian summer of human history, with nothing to look forward to but the nuclear winter' to close the account."
The first edition of War, which was based on the author's seven-part television series of the same name, was published in 1985 and quickly assumed classic status. This new edition sees some massaging and re-ordering of the old edition's chapters, as well as significantly expanded and up-to-date content on terrorism. In fact, the entire book has grown, from 272 pages to a hefty 484. (That such an expansion was warranted by events of the last two decades is in itself vaguely disquieting.) What hasn't changed, however, is Dyer's commitment to the answering of a key question: Is war an ineradicable part of our genetic make-up, or is it merely an ancient institution that can, with tremendous and concerted effort, be abolished?
Studies of Australian and Amazonian hunter-gatherer societies that persisted into the nineteenth and twentieth centuries give us some idea of how life was for our forbears, and the news is hardly surprising. Inter-tribal warfare exhibited by both groups was constant-enough to drive some tribes to extinction. As we travel back in time through the fossil record, examining the lives of human and proto-human ancestors, the evidence of our killing one another never goes away. The 100,000-year-old remains of Neanderthals often suggest that death came from spears and other stabbing weapons; the 750,000-year-old remains of Homo erectus often suggest that death was delivered by club blows to the skull. Perhaps the most depressing fact to be taken from all of this is that chimpanzees also practice the deliberate, systematic killing of their own kind, and their evolutionary line diverged from ours over half a million years ago. As Dyer argues, "modern human beings did not invent warfare. We inherited it."
The warfare practised by the above-mentioned groups was undisciplined, poorly organized, and relatively uncommitted. Skirmishes, dawn raids, and ambushes yielded relatively low casualty rates for any one given encounter. But then, between five and six thousand years ago, we see a massive disruption of this trend: new civilizations spring up, and with them takes place the "first truly large-scale slaughter of people in human history." This era saw the battle become a "mass psychodrama" wherein opposing ranks of men closed with one another in a merciless struggle that could kill thousands in the space of half an hour. "And the question we rarely ask," writes Dyer, "because our history is replete with such scenes," is as follows:

"how could men do this? After all, in the hunter-gatherer cultures we all come from, they could not have done it. Being a warrior and taking part in a carefully limited battle with a small but invigorating element of risk is one thing; the mechanistic and impersonal mass slaughter of civilized warfare is quite another, and any traditional warrior would do the sensible thing and leave instantly."

The hallmarks of civilization-the surplus of resources, the top-down hierarchical command, the large populations of men to draw upon for armies-enabled a sterner, more ruthless type of combat that, once started, could not be de-escalated or abandoned. Dyer traces the power struggles from antiquity through the Dark and Middle Ages, past the dawn of the nation state, and into the "total war" that marked the early twentieth century. Ultimately, he's left to wonder whether civilization wasn't an unwise development. "Human beings were doing quite nicely without it . . . and seemed set for a successful run of some millions of years. Here we are only ten thousand years into the experiment, facing . . . the potential extinction of the human species."
Dyer's clear language and convincing case building tow the reader along until we bump up against the Cold War-an era with war doctrines of such "baroque and self-referential complexity" that even his efforts to elucidate them are stymied. His chapter, "A Short History of Nuclear War" is largely a description of measures and countermeasures devised by brain trusts and policy wonks. Unwieldy acronyms fill the page: SAC, RAND, SIOPs, MAD, SALT, MIRV, TTAPS, ABM, and START. The rhetoric employed by the politicians and their analysts is often tortuous and euphemistic; their thinking seems deluded, even psychotic. This is the era that gave us Thomas Schelling's classic formulation on pre-emptive attack: "He thinks we think he'll attack; so he thinks we shall; so he will; so we must." This is the era in which Carl Sagan posited that a nuclear war threatens the lives of over 500 trillion people-everyone now living, plus all of our descendants over the course of an estimated evolutionary timeline. Unreality pervades the entire period. Dyer has trouble making sense of it all because there's little sense to be had.
Much more instructive is his writing on guerillas and terrorists. Any member of the Bush administration with free time between Bible-study sessions would be well advised to examine three particularly pertinent arguments that Dyer makes. One: History has shown that attempts by guerilla forces to topple governments have an abysmally low rate of success-except when the government in question has been emplaced by a foreign, occupying power. Two: The most effective terrorist organizations use "political jiu-jitsu", tricking their enemies into a ruthless militaristic response that can only discredit them and drive new converts to the terrorist cause. Three: The seeming monopoly the Western governments have had on democracy owes less to our inherited Christian/Greco-Roman values, and more to the spread of mass media forms that foster exchange and debate. If it is not quite utter folly to bring democracy forcibly to the rest of the world, it will certainly be proven a redundant exercise as media technologies continue to infiltrate formerly closed societies.
With the dawning of the nuclear age in 1945, Einstein observed rather ominously that "Everything has changed, except our way of thinking." Dyer elaborates in his final chapter, explaining that "our intelligence tends to produce technological and social change at a rate faster than our institutions and emotions can cope with." What's needed, he says, if we are to overcome our genetic destiny and end war, is "a final act of redefinition," an expansion of our "moral imagination" that embraces "the whole of mankind." Dyer sees the forming of a world government-one to which all nations would surrender their sovereignties-as the only solution to the mistrust and brinkmanship that currently threaten us. I envy Dyer for his optimism. And I envy the generation he envisions who claims victory in its war on war-the new and improved humanity that will, to borrow from Sassoon's The Rear-Guard, climb "through darkness to the twilight air/Unloading hell behind him step by step."