I hope this is not the case. I believe that a military alliance of sort would be plausible, but the integration of the 4 states into 1 country is not realistic. There are political, linguistic , and social differences that come to pale. In addition, i doubt that some 70 million Thais, who are rather nationalistic , would sign the waver of their independence to form a union with Viet Nam and the 2 much smaller nations , Cambodia and Laos.
@
NiceGuy , Thailand is a constitutional monarchy, so is Cambodia. Whereas Laos and Vietnam are Communist. It would be easier, perhaps, if Laos and Vietnam were to do union. But Cambodia and Thailand? Do you think so? I welcome your input to my query.