[Video transcript]

Water shortage is a recurring problem for farmer Homla Thakur. Rain has been scant in recent years. 

He owns a 2-hectare farm in the southeastern province of Sindh in Pakistan.  

Nearby, the country's largest river, the Indus, is running low. 

And the news that neighboring India has vowed to cut water supplies from this critical river has left farmers like Thakur in shock.   

Homla Thakhur, farmer: "If they stop the water, all of this will turn into desert, the whole country. The basic issue is water. Nothing is possible without water." 

India walked away from the Indus Water Treaty after a shocking attack on tourists in the Indian-administered Kashmir on April 22. India linked the attack to Pakistan. 

The Indus is a river system with numerous tributaries that stretch from Tibet to the southernmost tip of Pakistan. 

According to the water-sharing treaty, signed by Delhi and Islamabad in 1960 and brokered by the World Bank, Pakistan has control over the Indus, the Chenab and the Jhelum rivers. India, the upstream country, has to let most of the waters of those rivers flow freely to Pakistan. 

The treaty has survived decades of war and conflict — till now. Leaving Pakistan, the downstream country, worried for its survival. 
The Indus basin supplies water to 80% of Pakistan's agriculture. A sector that contributes nearly 25% of Pakistan's GDP. 

Pakistanis are concerned India is "weaponizing" water.

Bilwal Bhutto Zardari, Pakistan's former foreign minister: "My biggest concern is we're already locked in generations of conflict. We have been, generation after generation, for one reason or another, and we hope to work together to be able to address all those issues through the past. By exiting the Indus Water Treaty, I believe we're locking future generations into a brand-new context of conflict between India and Pakistan, and that must not happen."  

Experts argue it's nearly impossible for India to block the flow of water over night. But over time, with new dams and hydro power plants and canals, Pakistan’s water supply could significantly dwindle.

The suspension also means that India will stop sharing crucial information on the release of water and on flood alerts.

An alarming development for a region that is among the most affected by extreme weather events, and where working together could benefit more than a billion people who are bearing the direct consequences of climate change.