Currently BTC.COM[1] and AntPool[2] combined make up 42.5% of the network and both are both owned by Bitmain, a company headquartered in Beijing.
ViaBTC[3] is also a Chinese mining company operating out of Shenzhen and has 10.1%. I'm not going to bother checking the rest since that's already 52.6% of the network controlled by 2 companies under 1 authoritarian regime.
[0] https://blockchain.info/pools
[1] https://en.bitcoin.it/wiki/BTC.com
