International water conflicts are a prisoner’s dilemma fundamentally rooted in geopolitics. Neither up nor downriver states can live without it, and water is the lifeblood of development and economic growth. Yet one (upriver) state has a fundamental advantage over the other (downriver) state. All riparian states should cooperate to achieve the most sensible maintenance of their shared resources, but this is easier said than done, and there will always be a temptation for upriver states to press their advantage at the expense of others, especially in an era when climate change is altering longstanding ecological certainties.

This article briefly examines three international water conflicts; in each one, competition over limited water resources risks future inter-state conflict.

China-India: The Brahmaputra River

The Brahmaputra River is a 2,900 km river that originates in Tibet and flows through India’s Arunachal Pradesh state, before merging with the Ganges and draining into the Bay of Bengal in Bangladesh. It is considered an important resource in all three countries that it flows through: for energy-hungry China, it provides hydroelectricity; and for India and Bangladesh, the river is a key agricultural lifeline that traverses densely populated and arid regions.

Like all of the world’s rivers, the waters of the Brahmaputra are a finite resource, and one that is being strained by growing freshwater demand in both up and downriver states. For India, the Brahmaputra is particularly important to the agricultural industry in the Assam plains, where it supports the livelihoods of an estimated 27 million people. China on the other hand has tapped into the river’s electricity-generation potential by building a series of hydroelectric plants on the Tibetan Plateau. These include:

• Yamdrok Hydropower Station (operational in 1998; 112.5 MW capacity);
• Zhikong Hydropower Station (2007; 225 million cubic meter reservoir, generating 100 MW);
• Pangduo Hydropower Station, or ‘Tibetan Three Gorges’ (2013; 1.17 billion cubic meter reservoir, generating 160 MW);
• Jiacha Hydropower Station (under construction; 320 MW);
• Zangmu Dam, the world’s highest-altitude hydropower station (2015; 510 MW);
• Mapcha Tsangpo Dam (under construction);
• A proposed ‘super dam’ on the Great Bend of the Brahmaputra, which would become the largest hydropower project in the world

The potential for these projects to reduce the downriver flow of the Brahmaputra, whether intentionally or unintentionally, remains a source of geopolitical tension between China and India. Some steps have been taken toward the shared management of the Brahmaputra River, notably a 2002 memorandum of understanding (MoU) whereby China agreed to share hydrological data on water flow in China’s territory. However, in an illustration of how easily these shared ecological issues can spiral into international water conflicts, the 2002 agreement was suspended by Beijing when the two militaries clashed at the contested Doklam Plateau in 2017.  Though the 2002 MoU has been renewed three times, most recently in 2018, New Delhi and Beijing have yet to agree upon a comprehensive management agreement. And while many experts have argued and demonstrated that the hydrological profile of the Brahmaputra makes it ill-suited for coercive upstream manipulation (the river gathers momentum as it flows downstream), the Brahmaputra remains a potential source of friction between two of the world’s rising powers, if anything because of how the specter of water conflict looms ever larger in their strategic thinking, and even more so in the era of climate change.

Ethiopia-Egypt: Grand Ethiopian Renaissance Dam and the Nile River

In 2011, the Ethiopian government announced plans to build the Grand Ethiopian Renaissance Dam (GERD) – a $4.1 billion, 5,000 MW-capacity hydroelectric dam on the Blue Nile near the border with Sudan. The dam is meant to capitalize on Ethiopia’s considerable hydroelectric potential and provide electricity for not just Ethiopians but populations throughout the Horn of Africa. However, there are fears that the dam will simply trade one problem for another. And by shoring up its energy supply, Ethiopia might be jeopardizing its water security by increasing the volatility of a river that already has a long history of being impossible to predict.

The potential downriver impacts on water flow are of grave concern to Egypt, which views the Nile as the lifeblood of not just its agricultural economy but civilization, and unsurprisingly has fiercely opposed the construction of the Grand Ethiopian Renaissance Dam from the start. Cairo’s legal argument hinges on water treaties from 1929 and 1959 guaranteeing Egypt two-thirds of the Nile’s waters along with the right to veto any upstream projects. This right was ignored when Ethiopia went ahead with construction of the dam, though Addas Ababa was never party to the treaties, which themselves were negotiated with Britain on behalf of its colonies at the time.

Subsequent efforts to foster a multilateral approach to developing the Nile basin have failed, as evidenced by the 2010 Cooperative Framework Agreement that saw upriver countries join together against downriver countries (Egypt, Sudan) who refused to give up their historical rights despite changing economic power dynamics in the region.

The Grand Ethiopian Renaissance Dam began filling in 2020 and first generated electricity in 2022, later reaching a total electricity output of 1,550 MW in late 2024. The geopolitics of the dam remain fraught, and it stands as one of the world’s most volatile water conflicts, even producing ripple effects in the Sudan civil war as Cairo seeks out a partner in Khartoum who will maintain a united front against Addas Ababa on opposing the GERD.

Turkey-Iraq: Ilisu Dam and the Tigris River

Part of the Erdogan government’s Southeastern Anatolia Project, construction of the Ilisu Dam began in 2019 on the Tigris River near the border of Syria. The dam belongs to a long line of Turkish projects meant to tap into the hydroelectric potential of both the Tigris and Euphrates rivers, and it is expected to generate 1,200 MW, or roughly 2% of Turkey’s energy needs.

The Southeastern Anatolian Project entailed the construction of some 22 dams and 19 hydroelectric plants in the Tigris-Euphrates basin, so this is an international water conflict that has been brewing for quite some time. The big loser amid Turkey’s upstream activities is Iraq and, to a lesser degree, Syria. Iraq has historically enjoyed the lion’s share of these rivers’ waters, which have historically supplied the seasonal marshlands needed to grow food. But these waters have been receding over the past decade, even well before the Ilisu Dam’s completion. In fact, northern Iraq and Syria were wracked with such severe droughts leading up to 2014 that some analysts believe the resulting socioeconomic upheavals contributed to the rise of Islamic State.

The Ilisu Dam and other upstream projects in the Tigris-Euphrates basin continue to be a source of tension between riparian states, and the dam was recently cited by Iraqi Prime Minister Haidar al-Abadi as a factor that is worsening Iraq’s current drought. Climate change is likely to worsen this water conflict over time. The UN ranks Iraq as the fifth most vulnerable country in the world to climate change, and by some estimates the Euphrates River is at risk of drying up entirely by as early as 2040.