Squirt gun. While leaders in Washington have been war-gaming the national security risks of climate change, they’ve only started to connect the dots to the closely related threats emanating from the growing crisis of global freshwater scarcity. At first blush, water and national security may not seem to be interlinked. But the reality, as narrated in my new book WATER: The Epic Struggle for Wealth, Power, and Civilization, is that the unfolding global water crisis increasingly influences the outcome of America’s two wars, homeland defense against international terrorism, and other key U.S. national-security interests, including the transforming planetary environment and world geopolitical order.

Former U.N. Secretary-General Boutros Boutros-Ghali famously predicted 25 years ago that the “next war in the Middle East will be fought over water.” While that has yet to come to pass, the greatest present danger stems from failing nation-states — and not just in the bone-dry Middle East. With world water use growing at twice the rate of human population over the last century, many of the Earth’s vital freshwater ecosystems are already critically depleted and being used unsustainably to support our global population of 6.5 billion, according the 2005 Millennium Ecosystem Assessment, and the situation can only be expected to get worse as the population pushes toward 9 billion by 2050. As great rivers run dry before reaching the sea, groundwater is mined deeper and deeper beyond replenishment levels, and water quality erodes with growing pollution, an explosive fault line is cleaving between freshwater Haves and Have-Nots across the political, economic, and social landscapes of the 21st century.

Among the water Have-Nots are the 3.6 billion who will live in countries that won’t be able to feed themselves within 15 years due largely to scarcity of water — likely to include giant India. Throughout history, states that have been unable to feed themselves with homegrown or reliably imported cheap food have stagnated, declined, and often collapsed, with grievous adjustments in living standards, population levels, and regional turmoil.

Health and humanitarian crises are likely to emanate from the dark side of the Have-Not divide where 1 billion abject poor lack regular access to clean, fresh water for minimal needs and 2.6 billion don’t have basic sanitation. Upriver water Have states increasingly exert control over the precious water flows to their dependent neighbors downstream, while within nations the wealthy and those with greatest political clout commonly enjoy the formidable competitive advantage of better, and often subsidized, access to the best water resources. Global warming exacerbates the water crisis with extreme, unpredictable floods, droughts, glacier melts, storm swells, and other water cycle–related depredations that fall disproportionately on already water-insecure, Have-Not regions and overwhelm existing, fragile water infrastructures. Such dislocating events are expected to create 150 million environmental refugees within a decade.

A tumultuous adjustment to the freshwater scarcity crisis lies ahead, and in our global society the feedback effects will buffet even the security of distant nations. Two cases from the headlines — Yemen and Pakistan — illustrate some of the problems and challenges.

Yemen

Globe. Arid Yemen is an impoverished, failing state, home to al-Qaida in the Arabian Peninsula, which helped to train and arm the would-be Detroit-bound, Christmas suicide bomber from Nigeria. The Yemeni government is not much better than a large, corrupt tribe competing for control of the nation’s diminishing resources through patronage payoffs and proxy alliances with other strong tribes. There is warfare in the north between Houthi tribesmen and Saudi-backed government forces, while politically and economically disaffected southerners are trying to secede. The government is also battling al-Qaida, which flourishes in ungoverned no-man’s-lands.

Terrorism — which claimed 17 U.S. sailor lives in the attack in Aden Harbor on the USS Cole in 2000, and was beaten back for a few years with the help of U.S. drones — is resurgent. The Yemeni government’s policy of routinely releasing captured or repatriated terrorists after little more than a promise not to do it again frustrates the Obama administration’s efforts to shut the Guantanamo Bay prison, where about half of the remaining 200 prisoners are Yemeni.

One of the world’s most dire freshwater scarcity crises underlies Yemen’s extreme poverty and faltering state. The average Yemeni lives at eight times below the world freshwater availability poverty line, and has 1/20th the world average. Less than half have access to enough clean, fresh water for basic needs, while five-sixths lack adequate sanitation. Illegal well drilling is ubiquitous. Yet when the government tried to remove state subsidies for the diesel fuel powering the illegal pumps, riots forced it to desist. The lion’s share of the groundwater is commandeered (and used wastefully in flood irrigation) to grow the cash crop qat, a narcotic stimulant chewed by Yemeni men and an integral part of Yemeni culture.

The net result is an ecological and human catastrophe unfolding in slow motion: Water tables around the country are plunging — in many places two to four times faster than the natural replenishment rate. Soaring 7 percent annual population growth, adding to the current 23 million Yemenis, compounds the water scarcity crisis. As much as two-thirds of rural violence, including some deaths, is related to water. As life in rural areas grows untenable, Yemenis are crowding into already swollen cities, where water riots are not uncommon and mosques dispense minimum free water as charity to the poorest. In the capital, San’a, 100 of the 180 wells in use a decade ago have run dry. Within just five to 10 years, it is widely predicted to become the world’s first capital city to literally run out of water.

To try to retain some control, the government delegated power over water to local authorities and urban water companies. Al-Qaida is strongest in places like ancient Marib and Shabwa where no water companies operate, and it gains the support of the populace by providing health care and helping to dig wells. What viable diplomatic policy America and its allies can pursue in such a situation is unclear, as international financial aid simply disappears down the government’s sieve of corruption.

Pakistan

Earth. As dangerous as Yemen is as a failed state, it pales in comparison to Pakistan, which is nuclear-armed, Taliban-besieged, regionally fractious, and severely water fragile. Osama bin Laden and Al-Qaida’s core leadership are believed to be hiding out in its rugged northwest regions.

American leaders had a big fright in April 2009 when Muslim fundamentalist Taliban fighters broke out of the northwestern provinces and struck within 25 miles of the Indus River’s giant Tarbela Dam, a critical site they’d attacked through terrorism before, and only 30 miles from the capital, Islamabad. The Tarbela Dam is the strategic heart of Pakistan’s irrigation, hydropower, and flood-control network. If the Taliban damaged or took control of the giant dam, and gained critical leverage over Pakistan’s food and energy security, the government’s viability would be imperiled.

While Pakistan’s American-trained elite counterterrorism forces and air power quickly rallied to beat back the Taliban, the U.S. responded to the Taliban’s show of strength in the spring of 2009 by accelerating its $7.5 billion five-year aid package to Pakistan — the lion’s share of which is focused on rehabilitating the nation’s perilously deteriorating and inadequate agricultural and hydropower waterworks. During her tumultuous October 2009 visit to Pakistan, Secretary of State Hillary Clinton was repeatedly warned about the nation’s impending freshwater crisis.

At the heart of Pakistan’s crisis is the Indus River, its water lifeline and foundation of its farm economy, which provides the livelihood for 60 percent of Pakistanis. It’s already so badly overused that its water rarely reaches its now dried-up delta, and its huge fertile irrigated basin cropland is heavily reliant on overpumped groundwater and in dire need of a refurbished drainage system to remove poisoning salts. The Indus River also faces an alarming loss of up to a third of its flow by 2025 from the global warming–induced melting of its source Himalayan glaciers. In the same period, moreover, the nation’s population will grow 30 percent more to 225 million. Global climate change is further menacing monsoonal Pakistan with more unpredictable and intense seasonal floods and droughts. In a country where the water-storage capacity to buffer prolonged drought and loss of hydropower is only 30 days — 1/30th as much as in the U.S. and 1/15th as much as in China — the effects of climate change can quickly become catastrophic and destabilizing.

Complicating Pakistan’s water crisis is that most of its water originates outside its borders, in archenemy, nuclear-armed India — with whom it has fought several wars and still heatedly disputes the Kashmir border region — as well as in Afghanistan and China. The Indus water dispute with India, which helped trigger the first war between the countries, was resolved with a 1960 treaty. But under the strain of population growth and climate change, the treaty is in dire need of renegotiation. One source of tension is that both countries are building new hydropower dams on Indus tributaries in the Kashmir. Pakistan is also highly suspicious of India’s increased aid to Afghanistan for dams on rivers that flow into Pakistan; it fears it is an Indian subterfuge to put Pakistan in an east-west hydrological vise once America leaves Afghanistan. For their part, the Pakistanis have awarded their dam contract to China, India’s adversary with whom it has its own water disputes and testy political relations.  

The chessboard of Pakistan’s destiny is immensely complex, of course. But how it manages its critical water challenges — both from internal and external pressures — is one of the paramount variables in whether it will hold together as a coherent nation-state. Given its nukes, radical Muslim fundamentalists, and regional stature, what happens to it is of grave significance to American national security and Asian regional security.

The global water crisis is unfolding in many other places around the world, and in many different ways, posing vital national security challenges to the U.S.  Israel’s conflicts with Palestinians and Syria include contentious disputes over the vital water supplies of the West Bank and Golan Heights, which Israel won in the 1967 war and which today account for two-thirds of Israel’s total freshwater. Iraq’s national viability and prosperity depend significantly on how much water its upstream neighbors Syria and Turkey (the Middle East’s rising water superpower) permit to flow downstream. How tightly China, in its dam-building frenzy for economic growth, squeezes the waters from the 10 major Asian rivers originating in its Tibetan plateau will affect the prosperity and political robustness of downstream nations across Asia, China’s geopolitical status, and with it, U.S. national security interests. Whether and how big a food importer India becomes as its own water management runs short will affect global food prices, and conditions of famine and health, in food import–dependent countries worldwide.

Water and national security may not seem at first to be interconnected. But they are-increasingly so as the global freshwater scarcity crisis deepens.