I guess you were probably in a coma during the Cold War, eh?

j/k Soviet Union was a very powerful communist country with lots of resources and very big military. We were very, very afraid of them. I'm pretty certain that we came close to a ICBM shootout between the U.S. and the U.S.S.R. a few times, which would have effectively destroyed most of the world.
This "diplomacy" and "economic growth" is bringing in plenty of money and technology into China right now. Since, like forever, countries in the West has been keeping keen eye on high tech, especially computer related, from being stolen by the Chinese spies. I'm sure you can guess what the Chinese are trying to do with the latest chip they stole from the West, no, it's not for a new microwave oven they are working on.
Finally, take a look at how the Chinese government treat their own citizens. At times, they act like North Korea with bit of U.S. influence. As long as the current administration is in charge, I do not trust them. With their economic power rising, they will be able to influence other nations with money, also. They already started pressuring Taiwan with this, just week or two ago.
P.S. Big communist military in Far East might not be any threat to you, since you live in Scotland. Put your self in the shoes of Taiwan or Japan, which are in territorial dispute with China. Chinese Navy vessels, subs are invading our EEZ all the time. Richer, both financially and technologically, China is very intimidating to some.