The Indus Waters Treaty (IWT) of 1960 has been seen as an example of a successful transboundary water-sharing treaty between two hostile countries. The IWT withstood many tests, including wars (1965, 1971 and 1999), military tensions and regular verbal spats between India and Pakistan, whose leaders faced tough questions on engaging in the IWT negotiations and signing the treaty. However, recent changes in bilateral relations and especially the accelerating impact of climate change have meant that the IWT is feeling further heat. The article re-examines details of the political history of the water-sharing agreement between India and Pakistan to show how and why, after drawn-out negotiations, India and Pakistan finally agreed to sign the World Bank-mediated IWT in 1960. The article then discusses specifically that because a major share of the common waters passes through the conflict-sensitive region of Jammu and Kashmir, this has continued to contribute to fresh manifestations of water-related disputes and cooperation between India and Pakistan.