Country of south-east Asia (8)
(Other definitions for vietnam that I've seen before include "country abroad" , "Asian country, divided north and south from 1954 to 1975" , "S.E. Asian republic" , "Country of south-eastern Asia" , "Cambodia is a neighbour" .)
(Other definitions for thailand that I've seen before include "Southeast Asian country" , "Phuket's location" , "SE Asian country" , "Country of southeastern Asia" , "Former Siam" .)