Mountains, which constitute the majority of global biodiversity hotspots, are most vulnerable to ecosystem collapse due to various natural and anthropogenic stressors. Notably, over 90% of geopolitical conflicts have unfolded in the regions with global biodiversity hotspots. The Himalaya, Tibet and Hengduan (HTH) mountains are apt examples where climate change meets geopolitical conflict and militarization. Here, I advance a fresh proposal and hope that the neighbouring nations could bring to bear the neutrality of transboundary conservation areas, as part of their diplomatic tools, to broker a lasting peace. The proposal advocates establishing a Greater Himalayan Peace Reserve (GHPR) for posterity and regional ecological and economic security. The proposed reserve embraces the HTH mountains embodying some of the most biodiverse regions of the earth. These mountains also play a central role in controlling regional climate, water security and agricultural productivity of South and Southeast Asia. The GHPR is envisaged to be a potential regional platform for conservation diplomacy, and a model foundational framework for global sustainability and peace.