With COP 25 ending on a disappointing note, the world has to move ahead despite the USA, before next year's deadline, as South Asia faces major environmental depredation. Meanwhile, can India mull a tougher approach to the Indus Waters Treaty? Dr. Uttam Sinha, Water & Environment Diplomacy Analyst discuss this key issue with Nilova Roy Chaudhury, Editor, India Review & Analysis.     Dr Uttam Sinha is Senior Fellow at the Nehru Memorial Museum & Library & the Institute for Defence Studies and Analyses, and is among India's foremost scholars on strategy and diplomacy related to water and the environment.    Nilova Roy Chaudhury is a senior journalist, currently Editor, India Review & Analysis journal