The top 25 destinations for US arms also includes: Saudi Arabia - by far the highest, United Arab Emirates, Qatar, Morocco, Turkey, Afghanistan. All of these ahead of the UK in 2018. Also Indonesia. The USA is far and away the world's largest arms dealer.

https://www.statista.com/statistics/248552/us-arms-exports-b...

The wars China has been involved in don't include most of the places you claim. Korea, Vietnam, Tibet - that's about it since the post-WW2 revolution.

https://en.wikipedia.org/wiki/List_of_wars_involving_the_Peo...

USA on the other hand has quite some list.

https://en.wikipedia.org/wiki/List_of_wars_involving_the_Uni...