From what I can tell, both sides recognise the McMahon Line (fourth map) as the de facto line of control, and India seems to claim that as its official border. Yet in some maps India includes areas beyond it too.
Note: I know that China doesn’t claim all of Arunachal Pradesh, it doesn’t claim the panhandle in the bottom right
The McMahon line does make sense as a de-facto border, and I wouldn’t be surprised if it is eventually officially recognized by both countries. But the Simla Convention that established it was one of those Unequal Treaties, signed by the British Raj and the Republic of China - both very notably not the current governments of the two countries in question. The question is unsettled enough that they fought a war over the issue.
You might think that it’s just mountainous frontier, who cares. But the Brahmaputra River runs most of it’s course through China, and is heavily dammed for hydropower. It also provides most of the water for Northeast India, so you can imagine what sort of water rights disputes that leads to. So it’s not quite as simple as “they just need to sit down and get it all sorted out”.
I know about the dispute in general and the McMahon (not to moot your point, but it was the self-declared independent Tibetan delegation who signed it; there was an ROC delegate but he refused to sign it).
But where is this line? Because I’m seeing multiple definitions: the “smoothed” line that OSM shows (first map), the “wiggly” line I see on most official maps (fourth map, Google Maps shows both the smooth and wiggly lines), and then some weird in-between in the third map.
I also discovered that Bhutan is a mess too
This 2015 map by the CIA still shows the claim Bhutan relinquished in the 80’s lmao
