Originally Posted By: Myridon
 Originally Posted By: Konditor
when there's an enormous, universally recognized landmark smack in front of our faces

... which is not generally called "the Chinese Wall".

I agree, since the original context has nothing to do with strength or greatness, nor does it have to do with flimsiness or charade like the insubstantial Chinese screens, but with impenetrable inscrutability. I have no evidence for it, it is entirely a guess, but my guess would be that the term is probably old, from the mid to late 19th century and refers to the prevalence of Chinese secret societies and Chinese solidarity on the goldfields and in business in Western countries in the face of prujudice and racism against them. Police experience this 'Chinese Wall' when investigating crimes in any close knit community, whether it be a migrant community, special interest community, religious community, or simply country hick small town.