Pakistan, Sept. 26 -- Part I argued that India's rise and its intensifying strategic competition with China are important reasons for Beijing to maintain its "all-weather friendship" with Pakistan. Yet these factors, significant as they are, do not fully explain the remarkable durability of the China-Pakistan partnership. There is a deeper and more enduring factor at work: Geography.

Geography provides another, and perhaps even more compelling, answer.

It is geography that places Pakistan at the intersection of South Asia, Central Asia, the Middle East and the Indian Ocean, making it relevant not merely to China's India policy but to Beijing's broader regional and global ambitions.

China's industrial heartland lies thousands of kilomet...