If they hadn't been pulverized by an earthquake, the Spartans of ancient Greece might have defeated the Athenians, changing the course of Western culture.
But for a volcano, the Panama Canal would be in Nicaragua. And if the modern Greeks and Turks had not helped each other after their own earthquakes five years ago, they might well still be mortal enemies instead of friendly neighbors.
As Asian nations reel from the tsunamis that struck two weeks ago, history suggests that the tragedy could engender political fallout - both good and bad - that will re-shape the region as surely as the giant waves redrew its coastlines.
"Some natural disasters are triggers for change; others are catalysts for change already under way," says Jelle Zeilinga de Boer, coauthor of a new book, "Earthquakes in Human History: The Far- Reaching Effects of Seismic Disruptions." But, he adds, "they lead to a sequence of other events that can last for centuries."
It is still far too early to predict the nature and scope of political change wrought by the tsunami. But the first tentative signs can already be seen: Asian governments have pledged to cooperate on a tsunami early-warning system. Indian and US naval forces are working together on the relief effort without the months of negotiations such cooperation would once have taken.
And while they are cautious, diplomats suggest that the recent catastrophe and subsequent relief work could jolt two regional conflicts - separatist wars in Indonesia's Aceh province, and in the northeast of Sri Lanka - onto new paths.
"This is a watershed" for Aceh, says Sidney Jones, Southeast Asia project director for the International Crisis Group. "The tsunami will change the dynamic of the conflict in a number of important ways."
Across the Indian Ocean in Sri Lanka, where the Tamil Tigers have been fighting for independence from the central government for 20 years and where the tsunami killed over 30,000 people, "this was definitely one of those events that change history," says Hans Brattskar, the Norwegian ambassador whose government brokered a cease-fire two years ago.
"We are in darkness now, but people are looking for rays of hope," he adds.
Greece and Turkey found such hope in 1999, when a massive earthquake in Turkey killed 15,000 people and the Greek authorities rushed to help. A few months later, Turkish rescue teams were first on the scene of an earthquake in Greece.
"Suddenly, the perception of the 'other' as evil changed," recalls Soli Ozel, who teaches politics at Bilgi University in Istanbul. "The earthquakes provided indispensable public support for the policy of rapprochement."
That policy, however, was already under way, he points out, and quiet diplomacy had begun to bear fruit. "The earthquakes came when the ground for rapprochement was already there, but they were a major catalyst" for improved relations that most recently included Greek support for Turkey's entry into the European Union, Dr. Ozel says. "You couldn't build public diplomacy on 30 years of vilification."
"Disaster diplomacy" was forestalled, however, in the wake of another earthquake - the one that leveled the Iranian city of Bam in December 2003.
Washington sent aid to Tehran despite its status as a member of the "axis of evil," and for a few days it appeared as though Elizabeth Dole might lead a high- visibility American delegation to Bam that could have smoothed the path to more substantive diplomatic contacts.
The Iranian government, however, turned down the visit with President Mohammed Khatami, cautioning that "humanitarian issues should not be intertwined with deep and chronic political problems."
Ilan Kelman, an expert at Cambridge University in England who studies the political implications of natural disasters, says that the Turkish and Iranian cases both suggest that "disaster diplomacy cannot work on its own. There has to have been some precedent or diplomatic activity."
Sometimes, he worries, "disaster diplomacy" may actually set back reconciliation by raising public expectations and hopes so high that they prove too great a burden for fragile relations. Such was the case, he suggests, with long-term enemies India and Pakistan in the wake of Pakistani President Pervez Musharraf's offer of help to Indian victims of the Gujarat earthquake in 2001.
Within six months, that gesture led to the first-ever meeting between an Indian and a Paki- stani leader, but their summit made little headway, and a year later the two countries were at the brink of war again.
Ancient and modern history offer many examples of the political impact of natural disasters, says Mr. Zeilinga de Boer, who teaches earth and environmental sciences at Wesleyan University in Middletown, Conn. For example:
• An earthquake in 464 BC that destroyed much of the city of Sparta, and a slave revolt soon afterward ("social upheavals often follow geological ones," says Zeilinga de Boer) significantly weakened the militaristic city-state in its rivalry with Athens. The quake "triggered Sparta's decline," he argues.
• An earthquake and tidal wave that killed 40,000 people in the Portuguese capital of Lisbon in 1755 - the most catastrophic in European history - prompted the French philosopher Voltaire and others to question the dominant philosophy of optimism on which the ancien régime was founded. The earthquake contributed to the intellectual ferment that produced the Enlightenment and the French Revolution.
• The manner in which Nicaraguan dictator Anastasio Somoza - along with his relatives and cronies - stole much of the international aid sent to rebuild the shattered capital, Managua, after a 1972 earthquake, fueled the sputtering Sandinista revolution that triumphed in 1979.
• In 1902, it was almost certain that the Central American canal linking the Atlantic with the Pacific would be built in Nicaragua. Work had already begun.
But that year, the Montagne Pelée volcano erupted on the Caribbean island of Martinique, killing 30,000 people. Panamanian lobbyists immediately sent each member of the US Congress one of the recently issued Nicaraguan postage stamps depicting the country's scenic volcanoes.
Congress voted for a Panamanian route for the canal.
Analysts do not expect that the tsunami that devastated south Asia will quickly bring the war- ring parties together in Aceh province or in Sri Lanka. "I don't think there is an opportunity for political reconciliation in Aceh because the animosity between the Indonesian military and the 'Free Aceh Movement' is deep," says Rizal Sukma, an analyst at the Center for Strategic and International Studies in Jakarta, a think tank close to the military.
But the tsunami will leave its political mark, insists Ms. Jones. For a start, the government has been obliged to open Aceh up to international aid groups for the first time, "which will act as a check on the worst kind of abuses," she says.
And as Jakarta rebuilds Aceh's local administration - notorious as the most corrupt in the country - the authorities "have an opportunity ... to create a government that could ease Acehnese resentment against Jakarta," Jones suggests.
On the other hand, "if there is skimming of aid, if cronies are appointed to government, that could give the insurgency the biggest boost it has ever had," she says.
In northeast Sri Lanka, where the Tamil Tigers and government troops have been observing an uneasy truce for two years, "we witnessed extraordinary cooperation between government officials and Tiger cadres" in distributing relief supplies, says Helen Olafsdottir, a member of the Scandinavian team monitoring the cease-fire. "We were stunned by the professionalism and good spirit."
But she doubts whether that attitude on the ground will change political leaders' outlook. "There has been a pop-song here about how we are all one, but politics goes on," she says gloomily.
Mr. Brattskar, the Norwegian ambassador, is also cautious. "We've seen signs of real cooperation, but the question is whether it will continue into the next phase of reconstruction," he says. "My hope is that we might be able to use the very practical cooperation to build the confidence that is needed in the longer term to bring the peace process forward.
"The fundamental political questions ... won't go away" because of the tsunami, Brattskar says. "But I hope the kind of human touch we have seen will build confidence at a political level."
[Editor's note: Some readers have challenged the opening sentence of this story on the grounds that Sparta eventually defeated Athens in the Peloponnesian War that followed the 464 BC earthquake. Jelle Zeilinga de Boer's thesis is that in the long run, despite that military victory, the earthquake and its consequences - especially the persistent unrest among Sparta's slaves - hobbled Sparta in its quest for power and influence in the region. What endured were the cultural, social, and political achievements of Athens, argues Professor de Boer in the book "Earthquakes in Human History: The Far-Reaching Effects of Seismic Disruptions."]