Pakistan cries 'what if China blocks Brahmaputra': How real is the threat and why India shouldn't blink

File photo of an Indian paramilitary soldier patrolling the Brahmaputra river near Guwahati.

In a desperate attempt to pressure India over suspension of the Indus Waters Treaty (IWT), Pakistan is now resorting to thinly veiled threats. In a strikingly alarmist statement, Rana Ihsaan Afzal, a senior aide to Prime Minister Shehbaz Sharif, warned that India’s decision to place the IWT in abeyance could provoke a chain reaction, with China potentially retaliating by blocking the Brahmaputra River’s flow into India.

“If India does something like this and stops the flow of water to Pakistan, then China can also do the same thing,” Afzal said during a television interview late last month. “If things like this happen, the entire world will be in a war.”

A few days later, Victor Zhikai Gao, vice president of the Center for China and Globalization in Beijing, told India Today that no country should treat others in a manner it would not accept for itself.

In the interview, the Chinese official pointed to Beijing’s control over the Brahmaputra, warning that just as Indian rivers flow into Pakistan, Chinese rivers flow into India, and any hostile action could invite similar retaliation.

Brahmaputra’s relevance for India

The Brahmaputra, known as the Yarlung Tsangpo in Tibet, is a transboundary river that originates in western Tibet, flows through Arunachal Pradesh and Assam in India, and eventually merges with the Ganges in Bangladesh. It is crucial for India’s northeast, not just for drinking water and agriculture, but also for energy generation and flood management.

Around 30 per cent of Assam’s irrigation and hydropower needs are met through the Brahmaputra and its tributaries. What may concern is the fact that unlike the Indus Treaty, there is no binding water-sharing agreement between India and China over the Brahmaputra.

China’s dam ambitions

China has announced to construct a super hydropower dam on the Yarlung Tsangpo near Medog, just before it enters India. The proposed dam, expected to be the world's largest, could significantly alter the river's flow, impacting agriculture, hydropower generation, and water availability in India's northeastern states.

Moreover, Beijing is obligated under a 2013 MoU to share hydrological data on the Brahmaputra and the Sutlej rivers with India during the monsoon season (May to October). This data is vital for India to predict floods in Arunachal Pradesh and Assam.

However, since 2022, China has stopped sharing real-time river data with India. This undermines disaster management efforts in India’s northeast, while violating the spirit of transboundary cooperation.

Assam CM slams Pakistan’s threat

Assam Chief Minister Himanta Biswa Sarma said that Pakistan was weaving a new "manufactured threat" narrative of what will happen if China stops Brahmaputra's flow into the country.

He clarified that though China has not announced any such move, but even if it happens, it would in fact help mitigate the annual Assam floods. He said that most of Brahmaputra's flow is generated due to downpour in northeast India while glacial melt and limited Tibetan rainfall contribute to only 30-35 per cent of the river's water flow.

In an X post titled ''What If China Stops Brahmaputra Water to India? A Response to Pakistan's New Scare Narrative'', he said, ''After India decisively moved away from the outdated Indus Waters Treaty, Pakistan is now spinning another manufactured threat: What if China stops the Brahmaputra's water to India?" ''Let's dismantle this myth -- not with fear, but with facts and national clarity," he added.

What If China Stops Brahmaputra Water to India?A Response to Pakistans New Scare NarrativeAfter India decisively moved away from the outdated Indus Waters Treaty, Pakistan is now spinning another manufactured threat:What if China stops the Brahmaputras water to India?
Himanta Biswa Sarma (@himantabiswa) June 2, 2025

Sarma pointed out that even if China were to ''reduce water flow (unlikely as China has never threatened or indicated in any official forum), it may actually help India mitigate the annual floods in Assam, which displace lakhs and destroy livelihoods every year''.

''Meanwhile, Pakistan, which has exploited 74 years of preferential water access under the Indus Water Treaty, now panics as India rightfully reclaims its sovereign rights,'' he said.

Sarma claimed that Brahmaputra is a river that grows in India and does not shrink.

He pointed out that China contributes only 30-35 per cent of the Brahmaputra’s total flow -- mostly through glacial melt and limited Tibetan rainfall.

The remaining 65-70 per cent is ''generated within India, thanks to the torrential monsoon rainfall in Arunachal Pradesh, Assam, Nagaland, and Meghalaya''.

Major tributaries like Subansiri, Lohit, Kameng, Manas, Dhansiri, Jia-Bharali, Kopili also contribute to it while additional inflow comes in from the Khasi, Garo, and Jaintia Hills via rivers such as Krishnai, Digaru, and Kulsi, Sarma said.

"At the India-China border (Tuting), the flow of the river is ~2,000-3,000 m³/s while in the plains of Assam like Guwahati, the flow swells to 15,000-20,000 m³/s during monsoon," he added.

Can China really ‘block’ the Brahmaputra?

Blocking or diverting a river like the Brahmaputra is not a matter of turning off a tap. It is geographically complex, economically costly, and politically risky.

The Brahmaputra carries massive volumes of water and sediment. Attempting to divert it through tunnels in the eastern Himalayas would be an engineering feat fraught with seismic and environmental dangers. Any diversion would impact Bangladesh and potentially flood Chinese territory if mismanaged.

Unlike Pakistan, India is not diplomatically isolated. Any aggressive water manipulation by China would be seen as a violation of international norms, trigger backlash from downstream countries like Bangladesh, and harm China’s Belt and Road narrative of “peaceful development.”

Should India worry?

India has consistently raised the Brahmaputra issue with China through bilateral channels and multilateral forums. It has accelerated hydroelectric projects on its side of the Brahmaputra, especially in Arunachal Pradesh, to assert riparian rights, build upstream storage capacity, and reduce vulnerability.

Meanwhile, the Indian agencies have been improving monitoring of Chinese dam-building via satellite imagery to stay ahead of surprises.

However, China’s dam at Medog, if built without transparency, could be used to manipulate seasonal flows to India. Moreover, New Delhi should keep in mind that it has no legally binding treaty with China over transboundary rivers, giving Beijing space to act unilaterally.

Why Pakistan’s threats ring hollow?

Pakistan’s attempt to involve China over the Brahmaputra is strategically misplaced since it is not a Brahmaputra riparian state. Its invocation of China is purely rhetorical – an attempt to scare India by leveraging Beijing’s shadow.

Islamabad’s fearmongering is the desperate gamble of a state that has run out of options. But it does serve as a useful reminder that India must prepare for worst-case scenarios, including Chinese river manipulation, whether deliberate or accidental.

India need not panic, but it must remain alert. Investments in infrastructure, satellite monitoring, international partnerships, and domestic river basin planning must continue with urgency.