Thucydides "Trap"

 Conflict that is ruinous

LONG historical precedent

refers to Historian Thucydides

who wrote about

Athens

and 

Sparta who set about to mutually destroy one another

________________________________________

President Xi is drawing parallel between

China as Athens

and Sparta ( U.S.A.) who ruinously tries to destroy

an equal or necessary co-regnant city-state power CENTER