Despite booming two-way trade, strategic discord and rivalry between China and India is sharpening. At the core of their divide is Tibet, an issue that fuels territorial disputes, border tensions and water feuds.

Beijing says Tibet is a core issue for China. In truth, Tibet is the core issue in Beijing's relations with countries like India, Nepal and Bhutan that traditionally did not have a common border with China. These countries became China's neighbors after it annexed Tibet, a sprawling, high-altitude plateau where, after waves of genocide since the 1950s, ecocide now looms large.

Take China's relations with India: Beijing itself highlights Tibet as the core issue with that country by laying claim to large chunks of Indian land on the basis of purported Tibetan ecclesial or tutelary links, rather than any professed Han Chinese connection. Indeed, since 2006, Beijing has a new name — "South Tibet" — for the northeastern Indian state of Arunachal Pradesh, which is three times the size of Taiwan and twice as large as Switzerland.