Crab....actually it was the Chinese way long before the French but the French did a complete job of annoying the Vietnamese.
Our POW's spent a lot of time in old French Prisons under the same conditions the French held the Vietnamese.
Odd....the Vietnamese are quite friendly to Americans now.....but still harbor really bad feelings towards the French.
You do recall the Brits stayed awhile in Vietnam at the end of WWII along with the Japanese and engaged in combat against the Viet Minh (Communists) later to be the NVA.
There is far more history there than many wish to admit.