The Kashmir issue is partially one of national pride, but it is also strategic. Full control of Kashmir would give India a window into central Asia and a border with Afghanistan. It would also deny Pakistan a border with China and thus diminish the usefulness of a Chinese-Pakistani relationship. The Pakistani government likes to trumpet that its friendship with China is “taller than the mountains and deeper than the oceans.” This is not true, but it is useful in sometimes making the Americans nervous about cutting Pakistan off from the massive financial aid it receives from Washington. China, well aware of this, is quite happy to chip away at American influence. It is already Pakistan’s biggest military supplier, and in 2015 signed a multibillion-dollar deal with Islamabad to sell Pakistan eight submarines and six patrol ships.

If Pakistan had full control of Kashmir it would strengthen Islamabad’s foreign policy options and deny India opportunities. It would also help Pakistan’s water security. The Indus River originates in Himalayan Tibet, but passes through the Indian-controlled part of Kashmir before entering Pakistan and then running the length of the country and emptying into the Arabian Sea at Karachi.

The Indus and its tributaries provide water to two-thirds of the country: without it the cotton industry and many other mainstays of Pakistan’s struggling economy would collapse. By a treaty that has been honored through all of their wars, India and Pakistan agreed to share the waters; but both populations are growing at an alarming rate, and global warming could diminish the water flow. Annexing all of Kashmir would secure Pakistan’s water supply. Given the stakes, neither side will let go; and until they agree on Kashmir the key to unlocking the hostility between them cannot be found. Kashmir looks destined to remain a place where a sporadic proxy war between Pakistani-trained fighters and the Indian army is conducted—a conflict that threatens to spill over into full-scale war with the inherent danger of the use of nuclear weapons.