For most of that time China was not a "large economy".
That said, your "50 years" number is conveniently eliding https://en.wikipedia.org/wiki/Sino-Vietnamese_War which was closer to 40 years ago. Just because China failed to invade successfully doesn't change the fact that it invaded.
As for China's future actions, we'll see what they are. So far, the territorial claims they are making are not looking like they will lead to peace in the future.
For the rest, the people not worrying about invasions by US/UK/Allies live in those countries, I expect.
I'm not sure I'd call that an invasion, it was a 3 week assualt on the border in response to Vietnam deciding to go overthrow and occupy Cambodia and Laos, both of whom were supported by China.
There's not enough room in the comments to write down the last 50 years of US and allies boots on ground adventures bringing "peace" to the world.
That said, your "50 years" number is conveniently eliding https://en.wikipedia.org/wiki/Sino-Vietnamese_War which was closer to 40 years ago. Just because China failed to invade successfully doesn't change the fact that it invaded.
As for China's future actions, we'll see what they are. So far, the territorial claims they are making are not looking like they will lead to peace in the future.
For the rest, the people not worrying about invasions by US/UK/Allies live in those countries, I expect.