system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does Mongolia still exist today, how hasn't it's massive yet virtually unpopulated land been taken?

The country is technologically around Dothraki level and it's huge land the size of India is populated by less than 3 million people.  
  
It also has basically no military and a piss poor economy.  
  
I could capture the capital of Mongolia myself with 500 Kangaroos.
gpt
It serves as a nice buffer zone between China and Russia. Russia and China seems to be friends in many aspects of geopolitics, but make no mistake, Russia is wary of China when it comes to Siberia.

For most of its recent history in the last century, Mongolia is under the Soviet sphere of influence. Some would actually say it was a Soviet puppet. So China couldn't really lay a claim on Mongolia during those times. When the Soviet Union collapsed, with various republics declaring independence like Kazahkstan, Uzbekistan, etc., it pretty much cemented Mongolia's status as an independent nation.

But China wouldn't dare lay a claim on Mongolia even after the Soviet collapse. Russia still exists and it has far more nuclear weapons than China. Mongalia may no longer be part of Russia, but Russia won't want China laying a claim on it. Siberia would be next if the Chinese claims Mongolia.

Oddly enough though, the same can be said to Russia as well. Russia can't now claim Mongolia because it may upset the Chinese. Russia would rather have an independent Mongolia and peaceful China, than having the two of them superpowers having a tug-of-war over Mongolia.