First used to justify our intervention in Vietnam , the theory predicted that all of Southeast Asia would fall to Communist rule if we failed to intervene .
Southeast Asia /location/location/contains Vietnam
RB VBN TO VB PRP$ NN IN NNP , DT NN VBD IN DT IN NNP NNP MD VB TO JJ NN IN PRP VBD TO VB .
Southeast Asia
LOCATION
Vietnam
LOCATION
/location/location/contains