But these new overland pathways also have the potential to fundamentally alter China’s role in South Asia and the entire strategic make-up of the region. Geopolitically, South Asia has long functioned more or less as an island rather than as part of a bigger continent. Any overland connections that South Asia has with the rest of the continent are, at best, tenuous and excepting a tiny proportion of trade that is carried overland to and from Eurasia, essentially all of South Asia’s connections with the rest of the world are by sea or air.
These geographic constraints have had considerable political, economic and strategic consequences for the region. One is in underpinning India’s role as South Asia’s predominant power. The relative lack of landward connections into the Eurasian continent also amplifies the importance of control over the maritime trade routes across the northern Indian Ocean.
Geography has also caused Eurasian states, such as China, to have very limited contact with their South Asian neighbours. Sitting on the other side of the Himalayas, China may as well have been on the other side of the world.
If a Chinese-Pakistan alliance confronts India by going around India's "long walls" in the west, India's Act East policy that could block Chinese naval efforts to reach Indian waters through the South China Sea and Strait of Malacca will be threatened by the need to devote resources to air and ground power in India's west.
This is a serious land problem for India that adds to the naval problem of Chinese anti-ship ballistic missiles that could strike waters around India from inside China. I know this is mostly portrayed as a problem for America, but India is no less at risk.
Although if China's initiative commits China to a path that requires air-supported ground power at the expense of air-supported naval power, that's good for America as long as India can hold their own.
This initiative will be huge when completed.
UPDATE: India's drive for naval supremacy in the Indian Ocean is surely necessary, but it could be for nought if China opens a major land front against India with China's OBOR initiative.