I am shocked that neither the article nor the discussion mentions that there were second century Roman trade artifacts recovered by French archeologists at Oc Eo[0] on the Mekong delta[1] (ancient Champa[2]; now An Giang, Vietnam). Champa was the major pre-Vietnamese society in Vietnam and Cambodia whose probable regional trading partners essentially correspond to the SEA cultural sphere currently using fish sauce. Apparently Columbus tried to reach it at one point! [3] Asian ancient history is fascinating.
[0] https://en.wikipedia.org/wiki/%C3%93c_Eo [1] https://sci-hub.tw/10.2307/3248251 [2] https://en.wikipedia.org/wiki/Champa [3] https://en.wikipedia.org/wiki/%C3%93c_Eo#Columbus'_search_fo...