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January 1, 2005


By Jared Diamond

Los Angeles -- NEW Year's weekend traditionally is a time for us to
reflect, and to make resolutions based on our reflections. In this
fresh year, with the United States seemingly at the height of its
power and at the start of a new presidential term, Americans are
increasingly concerned and divided about where we are going. How long
can America remain ascendant? Where will we stand 10 years from now,
or even next year?

Such questions seem especially appropriate this year. History warns us
that when once-powerful societies collapse, they tend to do so quickly
and unexpectedly. That shouldn't come as much of a surprise: peak
power usually means peak population, peak needs, and hence peak
vulnerability. What can be learned from history that could help us
avoid joining the ranks of those who declined swiftly? We must expect
the answers to be complex, because historical reality is complex:
while some societies did indeed collapse spectacularly, others have
managed to thrive for thousands of years without major reversal.

When it comes to historical collapses, five groups of interacting
factors have been especially important: the damage that people have
inflicted on their environment; climate change; enemies; changes in
friendly trading partners; and the society's political, economic and
social responses to these shifts. That's not to say that all five
causes play a role in every case. Instead, think of this as a useful
checklist of factors that should be examined, but whose relative
importance varies from case to case.

For instance, in the collapse of the Polynesian society on Easter
Island three centuries ago, environmental problems were dominant, and
climate change, enemies and trade were insignificant; however, the
latter three factors played big roles in the disappearance of the
medieval Norse colonies on Greenland. Let's consider two examples of
declines stemming from different mixes of causes: the falls of classic
Maya civilization and of Polynesian settlements on the Pitcairn

Maya Native Americans of the Yucatan Peninsula and adjacent parts of
Central America developed the New World's most advanced civilization
before Columbus. They were innovators in writing, astronomy,
architecture and art. From local origins around 2,500 years ago, Maya
societies rose especially after the year A.D. 250, reaching peaks of
population and sophistication in the late 8th century.

Thereafter, societies in the most densely populated areas of the
southern Yucatan underwent a steep political and cultural collapse:
between 760 and 910, kings were overthrown, large areas were
abandoned, and at least 90 percent of the population disappeared,
leaving cities to become overgrown by jungle. The last known date
recorded on a Maya monument by their so-called Long Count calendar
corresponds to the year 909. What happened?

A major factor was environmental degradation by people: deforestation,
soil erosion and water management problems, all of which resulted in
less food. Those problems were exacerbated by droughts, which may have
been partly caused by humans themselves through deforestation. Chronic
warfare made matters worse, as more and more people fought over less
and less land and resources.

Why weren't these problems obvious to the Maya kings, who could surely
see their forests vanishing and their hills becoming eroded? Part of
the reason was that the kings were able to insulate themselves from
problems afflicting the rest of society. By extracting wealth from
commoners, they could remain well fed while everyone else was slowly

What's more, the kings were preoccupied with their own power
struggles. They had to concentrate on fighting one another and keeping
up their images through ostentatious displays of wealth. By insulating
themselves in the short run from the problems of society, the elite
merely bought themselves the privilege of being among the last to

Whereas Maya societies were undone by problems of their own making,
Polynesian societies on Pitcairn and Henderson Islands in the tropical
Pacific Ocean were undone largely by other people's mistakes.
Pitcairn, the uninhabited island settled in 1790 by the H.M.S. Bounty
mutineers, had actually been populated by Polynesians 800 years
earlier. That society, which left behind temple platforms, stone and
shell tools and huge garbage piles of fish and bird and turtle bones
as evidence of its existence, survived for several centuries and then
vanished. Why?

In many respects, Pitcairn and Henderson are tropical paradises, rich
in some food sources and essential raw materials. Pitcairn is home to
Southeast Polynesia's largest quarry of stone suited for making adzes,
while Henderson has the region's largest breeding seabird colony and
its only nesting beach for sea turtles. Yet the islanders depended on
imports from Mangareva Island, hundreds of miles away, for canoes,
crops, livestock and oyster shells for making tools.

Unfortunately for the inhabitants of Pitcairn and Henderson, their
Mangarevan trading partner collapsed for reasons similar to those
underlying the Maya decline: deforestation, erosion and warfare.
Deprived of essential imports in a Polynesian equivalent of the 1973
oil crisis, the Pitcairn and Henderson societies declined until
everybody had died or fled.

The Maya and the Henderson and Pitcairn Islanders are not alone, of
course. Over the centuries, many other societies have declined,
collapsed or died out. Famous victims include the Anasazi in the
American Southwest, who abandoned their cities in the 12th century
because of environmental problems and climate change, and the
Greenland Norse, who disappeared in the 15th century because of all
five interacting factors on the checklist. There were also the ancient
Fertile Crescent societies, the Khmer at Angkor Wat, the Moche society
of Peru -- the list goes on.

But before we let ourselves get depressed, we should also remember
that there is another long list of cultures that have managed to
prosper for lengthy periods of time. Societies in Japan, Tonga,
Tikopia, the New Guinea Highlands and Central and Northwest Europe,
for example, have all found ways to sustain themselves. What separates
the lost cultures from those that survived? Why did the Maya fail and
the shogun succeed?

Half of the answer involves environmental differences: geography deals
worse cards to some societies than to others. Many of the societies
that collapsed had the misfortune to occupy dry, cold or otherwise
fragile environments, while many of the long-term survivors enjoyed
more robust and fertile surroundings. But it's not the case that a
congenial environment guarantees success: some societies (like the
Maya) managed to ruin lush environments, while other societies -- like
the Incas, the Inuit, Icelanders and desert Australian Aborigines -
have managed to carry on in some of the earth's most daunting

The other half of the answer involves differences in a society's
responses to problems. Ninth-century New Guinea Highland villagers,
16th-century German landowners, and the Tokugawa shoguns of 17th-
century Japan all recognized the deforestation spreading around them
and solved the problem, either by developing scientific reforestation
(Japan and Germany) or by transplanting tree seedlings (New Guinea).
Conversely, the Maya, Mangarevans and Easter Islanders failed to
address their forestry problems and so collapsed.

Consider Japan. In the 1600's, the country faced its own crisis of
deforestation, paradoxically brought on by the peace and prosperity
following the Tokugawa shoguns' military triumph that ended 150 years
of civil war. The subsequent explosion of Japan's population and
economy set off rampant logging for construction of palaces and
cities, and for fuel and fertilizer.

The shoguns responded with both negative and positive measures. They
reduced wood consumption by turning to light-timbered construction, to
fuel-efficient stoves and heaters, and to coal as a source of energy.
At the same time, they increased wood production by developing and
carefully managing plantation forests. Both the shoguns and the
Japanese peasants took a long-term view: the former expected to pass
on their power to their children, and the latter expected to pass on
their land. In addition, Japan's isolation at the time made it obvious
that the country would have to depend on its own resources and
couldn't meet its needs by pillaging other countries. Today, despite
having the highest human population density of any large developed
country, Japan is more than 70 percent forested.

There is a similar story from Iceland. When the island was first
settled by the Norse around 870, its light volcanic soils presented
colonists with unfamiliar challenges. They proceeded to cut down trees
and stock sheep as if they were still in Norway, with its robust
soils. Significant erosion ensued, carrying half of Iceland's topsoil
into the ocean within a century or two. Icelanders became the poorest
people in Europe. But they gradually learned from their mistakes, over
time instituting stocking limits on sheep and other strict controls,
and establishing an entire government department charged with
landscape management. Today, Iceland boasts the sixth-highest per-
capita income in the world.

What lessons can we draw from history? The most straightforward: take
environmental problems seriously. They destroyed societies in the
past, and they are even more likely to do so now. If 6,000 Polynesians
with stone tools were able to destroy Mangareva Island, consider what
six billion people with metal tools and bulldozers are doing today.
Moreover, while the Maya collapse affected just a few neighboring
societies in Central America, globalization now means that any
society's problems have the potential to affect anyone else. Just
think how crises in Somalia, Afghanistan and Iraq have shaped the
United States today.

Other lessons involve failures of group decision-making. There are
many reasons why past societies made bad decisions, and thereby failed
to solve or even to perceive the problems that would eventually
destroy them. One reason involves conflicts of interest, whereby one
group within a society (for instance, the pig farmers who caused the
worst erosion in medieval Greenland and Iceland) can profit by
engaging in practices that damage the rest of society. Another is the
pursuit of short-term gains at the expense of long-term survival, as
when fishermen overfish the stocks on which their livelihoods
ultimately depend.

History also teaches us two deeper lessons about what separates
successful societies from those heading toward failure. A society
contains a built-in blueprint for failure if the elite insulates
itself from the consequences of its actions. That's why Maya kings,
Norse Greenlanders and Easter Island chiefs made choices that
eventually undermined their societies. They themselves did not begin
to feel deprived until they had irreversibly destroyed their

Could this happen in the United States? It's a thought that often
occurs to me here in Los Angeles, when I drive by gated communities,
guarded by private security patrols, and filled with people who drink
bottled water, depend on private pensions, and send their children to
private schools. By doing these things, they lose the motivation to
support the police force, the municipal water supply, Social Security
and public schools. If conditions deteriorate too much for poorer
people, gates will not keep the rioters out. Rioters eventually burned
the palaces of Maya kings and tore down the statues of Easter Island
chiefs; they have also already threatened wealthy districts in Los
Angeles twice in recent decades.

In contrast, the elite in 17th-century Japan, as in modern Scandinavia
and the Netherlands, could not ignore or insulate themselves from
broad societal problems. For instance, the Dutch upper class for
hundreds of years has been unable to insulate itself from the
Netherlands' water management problems for a simple reason: the rich
live in the same drained lands below sea level as the poor. If the
dikes and pumps keeping out the sea fail, the well-off Dutch know that
they will drown along with everybody else, which is precisely what
happened during the floods of 1953.

The other deep lesson involves a willingness to re-examine long-held
core values, when conditions change and those values no longer make
sense. The medieval Greenland Norse lacked such a willingness: they
continued to view themselves as transplanted Norwegian pastoralists,
and to despise the Inuit as pagan hunters, even after Norway stopped
sending trading ships and the climate had grown too cold for a
pastoral existence. They died off as a result, leaving Greenland to
the Inuit. On the other hand, the British in the 1950's faced up to
the need for a painful reappraisal of their former status as rulers of
a world empire set apart from Europe. They are now finding a different
avenue to wealth and power, as part of a united Europe.

In this New Year, we Americans have our own painful reappraisals to
face. Historically, we viewed the United States as a land of unlimited
plenty, and so we practiced unrestrained consumerism, but that's no
longer viable in a world of finite resources. We can't continue to
deplete our own resources as well as those of much of the rest of the

Historically, oceans protected us from external threats; we stepped
back from our isolationism only temporarily during the crises of two
world wars. Now, technology and global interconnectedness have robbed
us of our protection. In recent years, we have responded to foreign
threats largely by seeking short-term military solutions at the last

But how long can we keep this up? Though we are the richest nation on
earth, there's simply no way we can afford (or muster the troops) to
intervene in the dozens of countries where emerging threats lurk -
particularly when each intervention these days can cost more than $100
billion and require more than 100,000 troops.

A genuine reappraisal would require us to recognize that it will be
far less expensive and far more effective to address the underlying
problems of public health, population and environment that ultimately
cause threats to us to emerge in poor countries. In the past, we have
regarded foreign aid as either charity or as buying support; now, it's
an act of self-interest to preserve our own economy and protect
American lives.

Do we have cause for hope? Many of my friends are pessimistic when
they contemplate the world's growing population and human demands
colliding with shrinking resources. But I draw hope from the knowledge
that humanity's biggest problems today are ones entirely of our own
making. Asteroids hurtling at us beyond our control don't figure high
on our list of imminent dangers. To save ourselves, we don't need new
technology: we just need the political will to face up to our problems
of population and the environment.

I also draw hope from a unique advantage that we enjoy. Unlike any
previous society in history, our global society today is the first
with the opportunity to learn from the mistakes of societies remote
from us in space and in time. When the Maya and Mangarevans were
cutting down their trees, there were no historians or archaeologists,
no newspapers or television, to warn them of the consequences of their
actions. We, on the other hand, have a detailed chronicle of human
successes and failures at our disposal. Will we choose to use it?

Jared Diamond, who won the 1998 Pulitzer Prize in general nonfiction
for "Guns, Germs and Steel: The Fates of Human Societies," is the
author of the forthcoming "Collapse: How Societies Choose or Fail to

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