In the last few years, tensions between the three nuclear-weapon states of India, China, and Pakistan have intensified, partly due to water and border issues (Johnson 2019). These tensions will only get worse due to two existential threats: the climate crisis, and the danger posed by nuclear weapons.

This is not a new situation; the water crisis and the threats posed by weapons of mass destruction (WMD) have ranked in the top five of the World Economic Forum’s Global Risks by Impact list nearly every year since 2012.

What is new is the growing realization that these threats are intertwined. Climate-triggered water scarcity is escalating the tensions between countries, especially in Asia, and consequently increasing the threat of nuclear war (Albinia 2020). At the same time, research over the past 10 years shows that even a so-called “limited” nuclear war involving less than 0.5 percent of the world’s nuclear weapons would cause catastrophic global climate disruption and a worldwide famine, putting up to 2 billion people at risk (Helfand 2013). According to the most recent research, the climatic effects of the smoke produced by an India-Pakistan nuclear war would not be confined to the subcontinent or even to Asia (Robock et al 2019). These global effects are in addition to the immediate death of 50 million to 125 million people in South Asia, depending on the weapons’ yield.

About 700 million people from five countries—India, Pakistan, China, Bhutan, and Bangladesh—live in three of the most densely populated river basins in the world: the Indus, Ganges, and Brahmaputra rivers. Potential conflict between nuclear-armed states over the water in two of these systems—between India and Pakistan over the Indus River, and between India and China over the Brahmaputra River—represents a truly global security threat.

Indus River conflict between India and Pakistan

The Indus River originates in the Tibetan plateau and is divided between Pakistan with about 60 percent of the catchment area, India with about 20 percent, Afghanistan with 5 percent, and about 15 percent in Tibet—also known as the Tibet Autonomous Region of China (Al Jazeera 2011). During the partition of British India, the borderlines between India and Pakistan were drawn following what was defined as the “Indus watershed” (Gardner 2018). The boundary commission set by the British awarded upstream control barrages situated close to the Line of Control to India, which regulated water flow into Pakistan. (A barrage is a diversion dam consisting of several large gates that can be opened or closed to control the water flow.) Both Pakistan and India rely heavily on the glacial melt and freshwater from the Indus that flows through the regions of Jammu and Kashmir for irrigation and electricity—contested areas claimed by both India and Pakistan. For this reason, the dispute and the ongoing tensions over Kashmir have transformed water into a national security issue for both countries.

The Indus water dispute has been an ongoing issue between India and Pakistan since the partition in 1947. In 1960, both countries signed The Indus Water Treaty, which was initiated and mediated by the World Bank. The Treaty defines India’s and Pakistan’s rights, restrictions, and obligations regarding the use of the Indus River, and it was considered an example of a successful mechanism for cooperation between countries until quite recently. However, the tension in the long-disputed territories of Jammu and Kashmir, increasing water stress caused by climate change, and the construction of hydroelectric power plants by India on one side and Pakistan on the other side are increasingly straining the Treaty and worsening the relationship between the countries.

For example, in 2016, India blamed Pakistani militants for attacking Indian army personnel in Indian-administered Kashmir and came close to ending the Indus water treaty. During the subsequent Indus Water Treaty meeting, India’s prime minister, Narendra Modi, declared that “blood and water cannot flow together at the same time” (Indian Express 2016). In response, Pakistan announced that an Indian revocation of the treaty could be taken as an “act of war.” The heated arguments and confrontations did not end up in a war on this occasion. But the dispute between the nuclear-armed nations of India and Pakistan over access and control over the water in the Indus rivers will intensify as climate change accelerates and water becomes more scarce.

The pace of this change can be seen by a few selected statistics. According to a National Geographic magazine article (Albinia 2020), approximately 18,495 glaciers help supply water to the Indus river. A study published by graduate student Joshua Maurer of Columbia University’s Lamont-Doherty Earth Observatory found that Himalayan glaciers melted twice as quickly in 2000-2016 as they did from 1975 to 2000 (Maurer 2016). By 2050, the temperature in the Indus basin is expected to rise by about 2 degrees Celsius (3.6 degrees Fahrenheit)—and in some places by as much as 4 to 5 degrees Celsius (7.2 to 9 degrees Fahrenheit)—causing more snow and glacial melt. Furthermore, in a 2019 assessment report by the International Centre for Integrated Mountain Development, at least a third of the huge ice fields which feed the Indus basin in Asia’s towering mountain chain are predicted to melt due to climate change. In the short term, this may lead to increased water flow as the glaciers melt and could cause an increased risk of flooding (Mohd et al 2021). Flow is expected to peak around 2050 but decline significantly after that.

Almost 45 percent of Pakistan’s population depends on agriculture for their livelihood, and water from the Indus supports 90 percent of the agricultural sector in the country. Similarly, many Indian states depend on the Indus for irrigation and electricity. Paradoxically, climate change has also resulted in increased monsoon rains in the region, causing catastrophic floods resulting in human loss and agricultural damage. Estimates by the World Bank predict that there will be 40 million climate migrants in South Asia by 2050 (World Bank 2021).

Brahmaputra conflict

The Brahmaputra River basin is based within China (50.5 percent), India (33.6 percent), Bangladesh (8.1 percent), and Bhutan (7.8 percent). It is a significant water source for more than 130 million people, including indigenous communities in all four countries (Wuthnow et al 2020). China holds a significant advantage over India—and India over Bangladesh—in their ability to control the Brahmaputra’s water flow. But as the climate changes (and the population increases), the rate of glacial retreat in the Himalayan region will increase, reducing the amount of groundwater and the water available in South Asia’s river basins.

Scientists from the Indian Institute of Technology, and also from India’s National Centre for Ocean and Polar Research, have found that average temperatures rose by 0.02 degrees Celsius (0.036 degrees Fahrenheit) each year between 2003 and 2015 across the whole basin (Padma 2020). As a result of decreasing rainfall and increasing temperature, water storage in the basin has decreased; for instance, annually, there has been a reduction in terrestrial water storage of 12.6 millimeters (0.49 inches) in the Indus-Ganga-Brahmaputra region. Furthermore, flood intensity, frequency, and severity in the Brahmaputra basin have increased due to climate change. For instance, the floods of 2009 affected almost a million people and killed over 200 people, while the flood in 2020 affected more than 3.3 million people and killed 85 people (Al Jazeera 2020).

In response to declining water supplies and to meet their increasing populations’ energy requirements, China, India, and Pakistan are building hydroelectric dams along the Brahmaputra and Indus River tributaries. This hydropower construction will affect the sharing of water  between the four countries and is another reason for the deteriorating relationship between India and China. (Unlike India and Pakistan, in the case of the Brahmaputra River, there is no water-sharing agreement between India and China.)

The conflict between the two nuclear powers of India and China has been escalating recently, in part due to the Brahmaputra water conflict. Most recently, in June 2021, the disagreement about building infrastructure on the border resulted in armed conflict that killed 24 soldiers from both sides. On November 6, 2021, the previous Chief of Indian Defense Staff, the late Gen. Bipin Rawat, warned that a “larger conflict” with China could not be ruled out if border confrontations and unprovoked military actions continue.

Geopolitics, conflicts, and the nuclear arms race in the region and globally

Meanwhile, growing tension between the nuclear countries in the region is contributing to a nuclear arms race, posing a security threat to regional and global stability. China has about 350 nuclear warheads, India has approximately 150 warheads, and Pakistan has 165 warheads. According to a recent Pentagon report, China is rapidly expanding its nuclear arsenal, and its authors wrote they anticipate that China “will have at least 1,000 warheads by 2030, exceeding the pace and size the Department of Defense projected in 2020” (US Defense Department 2021).

For its part, on October 27, India tested its long-range Agni-V Intercontinental Ballistic Missile, with very high accuracy and capable of striking targets at ranges up to 5,000 kilometers, or about 3,107 miles (Indian Express 2021). Furthermore, according to the Independent Congressional Research Service’s latest report—published in October 2021—India is collaborating with Russia to develop the BrahMos II, a hypersonic cruise missile. For its part, Pakistan has several new delivery systems in development, and with four plutonium reactors and an expanding uranium enrichment infrastructure, it has the potential to increase its arsenal.

The flip side: Water scarcity could be an opportunity to improve relations

Water scarcity in South Asia could lead to further armed conflicts and potential nuclear war.

However, it also presents an opportunity to improve relations and cooperation between and among China, India, Pakistan, and other countries. They are part of the problem and must work together to solve it. Regional and international cooperation is required more than ever to tackle all human security threats, including COVID, the climate crisis, and nuclear weapons. In addition, there could be national, regional, and international cooperation to combat climate change and adapt to its effects as agreed in the Paris Agreement. This includes providing financial support to developing countries and sharing clean technology that helps to reduce carbon emissions. When it comes to water scarcity, governments could focus on improving water use efficiency by adopting water-saving technologies such as micro-irrigation in crops cultivation, restoring water bodies, and reusing water whenever possible.

To find a solution to the Indus water conflict, India, Pakistan, and other interested countries should engage and resume their collaboration and revise the Indus Water Treaty to reassess water flow, climate change impacts, and water requirements. Furthermore, China and India have the opportunity to enter a dialogue over the Brahmaputra River conflict, and establish a bilateral or multilateral treaty—one that includes Bangladesh and Bhutan—to regulate the amount of water to be released, the building of dams, the preservation of water quality, and how best to coordinate water-sharing during times of drought and flooding.

It is equally important to directly address the nuclear threat in South Asia. The region’s countries must understand that nuclear weapons are the greatest threat to their safety. Therefore, they must strive to end their new arms race and work with the other nuclear-armed states to eliminate these weapons.

On January 3, 2021, the leaders of China, France, Russia, the United Kingdom, and the United States issued a joint statement on preventing nuclear war and avoiding an arms race. This joint statement and the commitment to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) are promising. However, the nuclear weapon countries should be leading by action for disarmament. March 2022 marks the 52nd anniversary of the entry into force of Article VI of the NPT, which obligates signatories to “pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and nuclear disarmament.” However, the nuclear-armed states are spending hundreds of billions of dollars to modernize their nuclear arsenals. This new race raises questions about the effectiveness of the NPT. Furthermore, to eliminate the existential threat of nuclear weapons, it is crucial to engage with all the nuclear weapons countries, including India, North Korea, Pakistan, and Israel, which are not signatories to the NPT. The Treaty on the Prohibition of nuclear weapons allows the nuclear weapon countries and non-nuclear-weapon countries to engage multilaterally and eliminate the existential threats of nuclear weapons.