Why is China spending 400 billion for a railway through empty mountains in Tibet?

After the Yarlung Tsangpo dam project announced earlier this year, China just kicked off another extremely strategic infrastructure project in Tibet that I've seen almost no-one discuss. Yet it'll likely cost 300 to 400 billion Yuan, far more than Tibet's entire annual GDP (RMB 276.5 billion in 2024).

It's a new rail line that connects Hotan (Hetian) in Xinjiang province to Shigatse (Xigazê) in Tibet (see my video below), going through almost the entire length of the Himalayas, alongside the Southern border of Tibet with India and Nepal.

It'll be one of the most expensive railway projects ever undertaken anywhere, especially when one looks at the number of people it serves: there are currently only 1/2 million people living on the line's path - virtually empty by China’s standards - meaning it's likely to cost close to 1M yuan per local inhabitant.

So why build such a rail line, when the cost is so over-the-top and the people it serves so few?

Because this project is extremely strategic for a few reasons.