Why is the US spying on Chinese workers? And why does it matter if the Chinese do business there? If China sanctions the UK, should China report on American wo

Why is the US spying on Chinese workers? And why does it matter if the Chinese do business there? If China sanctions the UK, should China report on American workers/politicians arriving in the UK? Would the US respect it if China sanctions a country? Also, doesn't the US surround China with military bases?