China has officially commenced construction of a controversial mega-dam project on the Yarlung Tsangpo River in Tibet, a move that has heightened tensions with India. The project, which includes five cascade dams, is estimated to cost 1.2 trillion yuan ($167 billion) and will be undertaken by the newly formed China Yajiang Group. This hydropower project is slated to be the world's largest, surpassing the Three Gorges Dam in terms of electricity generation capacity.

The Yarlung Tsangpo River, known as the Brahmaputra in India and the Jamuna in Bangladesh, is a vital water source for millions of people in the region, raising concerns about the dam's potential impact on downstream countries. Indian officials and experts have voiced fears regarding environmental degradation and the possibility of China using the dam to manipulate water flow into India, essentially giving China a "chokehold" on India's economy.

Concerns have been raised that China could use the dam to create "water bombs" by releasing large amounts of water during times of conflict, or to reduce water flow during dry seasons, leading to scarcity and endangering millions. Pema Khandu, the Chief Minister of Arunachal Pradesh, has called the project a "big threat" and an "existential threat" to the tribes and livelihoods in his state, warning of potential weaponization of the water. He also stated that China cannot be trusted because it is not a signatory to international water treaties that could enforce international norms.

In response to these concerns, the Chinese Foreign Ministry has maintained that the dam will not negatively impact downstream regions, emphasizing China's "responsible attitude" towards transboundary rivers. However, this has done little to assuage fears in India, where distrust of Chinese intentions remains high. Some experts believe that the water flow in the river is already under stress because of climate change, which is causing glaciers to melt.

India is taking steps to protect its water security by developing the Siang Upper Multipurpose Project, a 10 GW hydropower plant in Arunachal Pradesh. This project will serve as both a power generator and a strategic buffer to ensure water security.

Despite China's assurances, the project's scale and location near the Indian border have heightened geopolitical sensitivities, especially given recent tensions between the two countries. The potential for environmental risks, including the dam's location in an area prone to earthquakes and landslides, also adds to the concerns. Some experts have warned that building a dam this large could pose a major risk and disrupt the ecosystem, threatening biodiversity and forcing residents to relocate.

The Chinese government views the dam as a crucial component of its green energy strategy and its efforts to boost economic growth in Tibet. The project is expected to generate substantial revenue and create local employment opportunities, furthering regional development. However, critics argue that these benefits should not come at the expense of environmental sustainability and regional stability.