Click on the water conflict map to see some of Al Jazeera's coverage of an issue which could define 21st century strife
The author Mark Twain once remarked that "whisky is for drinking; water is for fighting over" and a series of reports from intelligence agencies and research groups indicate the prospect of a water war is becoming increasingly likely.
In March, a report from the office of the US Director of National Intelligence said the risk of conflict would grow as water demand is set to outstrip sustainable current supplies by 40 per cent by 2030.
"These threats are real and they do raise serious national security concerns," Hillary Clinton, the US secretary of state, said after the report's release.
Internationally, 780 million people lack access to safe drinking water, according to the United Nations. By 2030, 47 per cent of the world’s population will be living in areas of high water stress, according to the Organisation for Economic Co-operation and Development's Environmental Outlook to 2030 report.
Some analysts worry that wars of the future will be fought over blue gold, as thirsty people, opportunistic politicians and powerful corporations battle for dwindling resources.
Governments and military planners around the world are aware of the impending problem; with the US senate issuing reports with names like Avoiding Water Wars: Water Scarcity and Central Asia’s growing Importance for Stability in Afghanistan and Pakistan.
With rapid population growth, and increased industrial demand, water withdrawls have tripled over the last 50 years, according to UN figures.
"Water scarcity is an issue exacerbated by demographic pressures, climate change and pollution," said Ignacio Saiz, director of Centre for Economic and Social Rights, a social justice group. "The world's water supplies should guarantee every member of the population to cover their personal and domestic needs."
"Fundamentally, these are issues of poverty and inequality, man-made problems," he told Al Jazeera.
Of all the water on earth, 97 per cent is salt water and the remaining three per cent is fresh, with less than one per cent of the planet's drinkable water readily accessible for direct human uses. Scarcity is defined as each person in an area having access to less than 1,000 cubic meters of water a year.
The areas where water scarcity is the biggest problem are some of the same places where political conflicts are rife, leading to potentially explosive situations.
Some experts believe the only documented case of a "water war" happened about 4,500 years ago, when the city-states of Lagash and Umma went to war in the Tigris-Euphrates basin.
But Adel Darwish, a journalist and co-author of Water Wars: Coming Conflicts in the Middle East, says modern history has already seen at least two water wars.
"I have [former Israeli prime minister] Ariel Sharon speaking on record saying the reason for going to war [against Arab armies] in 1967 was for water," Darwish told Al Jazeera.
Some analysts believe Israel continues to occupy the Golan heights, seized from Syria in 1967, due to issues of water control, while others think the occupation is about maintaining high ground in case of future conflicts.
Senegal and Mauritania also fought a war starting in 1989 over grazing rights on the River Senegal. And Syria and Iraq have fought minor skirmishes over the Euphrates River.
Middle East hit hard
UN studies project that 30 nations will be water scarce in 2025, up from 20 in 1990. Eighteen of them are in the Middle East and North Africa, including Egypt, Israel, Somalia, Libya and Yemen.
"Water too often is treated as a commodity, as an instrument with which one population group can suppress another"
-Ignacio Saiz, Centre for Economic and Social Rights
Darwish bets that a battle between south and north Yemen will probably be the scene of the next water conflict, with other countries in the region following suit if the situation is not improved.
Water shortages could cost the unstable country 750,000 jobs, slashing incomes in the poorest Arab country by as much as 25 per cent over the next decade, according to a report from the consulting firm McKinsey and Company produced for the Yemeni government in 2010.
Commentators frequently blame Yemen's problems on tribal differences, but environmental scarcity may be underpinning secessionist struggles in the country's south and some general communal violence.
"My experience in the first gulf war [when Iraq invaded Kuwait] is that natural resources are always at the heart of tribal conflicts," Darwish told Al Jazeera.
The Nile is another potential flash point. In 1989, former Egyptian president Hosni Mubarak threatened to send demolition squads to a dam project in Ethiopia.
"The Egyptian army still has jungle warfare brigades, even though they have no jungle," Darwish said.
On the Nile, cooperation would benefit all countries involved, as they could jointly construct dams and lower the amount of water lost to evaporation, says Anton Earle, director of the Stockholm International Water Institute think-tank.
"If you had an agreement between the parties, there would be more water in the system," he told Al Jazeera. The likelihood of outright war is low, he says, but there is still "a lot of conflict" which "prevents joint infrastructure projects from going ahead".
Water scarcity, and potential conflicts arising from it, is linked to larger issues of population growth, increasing food prices and global warming.
There are two general views about how these problems could unfold. The first dates back to the work of Thomas Malthus, an eighteenth century British clergyman and author who believed that: "The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race."
In other words, more people and scant resources will invariably lead to discord and violence.
|View our special coverage of the population milestone
Recent scholars, including Thomas Homer-Dixon, have analysed various case studies on environmental degradation to conclude that there is not a direct link between scarcity and violence. Instead, he believes inequality, social inclusion and other factors determine the nature and ferocity of strife.
"Unequal power relations within states and conflicts between ethnic groups and social classes will be the greatest source of social tensions rising from deprivation," said Ignacio Saiz from the social justice group. "Water too often is treated as a commodity, as an instrument with which one population group can suppress another."
Bolivia, South Africa, India, Botswana, Mexico and even parts of the US have seen vigorous water related protests, says Maude Barlow, author of 16 books and a former senior adviser to the UN on water issues.
"The fight over water privatisation in Cochobamba, Bolivia did turn into a bit of a water war and the army was called in," Barlow told Al Jazeera. "In Botswana, the government smashed bore holes as part of a terrible move to remove [indigenous bushmen] from the Kalahari desert. Mexico City has been forcibly taking water from the countryside, confiscating water sources from other areas and building fotresses around it, like it's a gold mine. In India, Coke will get contracts and then build fortresses around the water sources," taking drinking and irrigation water away from local people. "In Detroit 45,000, officially, have already had their water cut off."
Strife over water, like conflicts more generally, will increasingly happen within states, rather than between them, Barlow says, with large scale agribusiness, mining and energy production taking control over resources at the expense of other users.
The IPPC, the UN panel which analyses climate science, concluded that: "Water and its availability and quality will be the main pressures on and issues for, societies and the environment under climate change."
Dealing with these pressures will require improved technologies, political will and new ideas about how humans view their relationship with the substance that sustains life.
"People have the right to expect access to a basic life resource like water by virtue of being human, regardless of the social situation they are born into," Saiz said. "Alongside the worrying development of water scarcity, I am hopeful that we will see increasing struggles to see access to water as a right, and not a priviledge."
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