In both VN and Korea there was nationalist motivation to reunite the countries and seek independence. Both NVN, N Korea like N China believed in International communism and wanted the riches of the capitalist in the south in all cases. The Chinese, and VN at least evolved into state capitalism, N Korea didn't.

Colonialism is a mixed bag, the out comes after independence depends greatly on which colonial power ruled. The USA and Australia were lucky.

Every normal man must be tempted, at times, to spit on his hands, hoist the black flag, and begin slitting throats. H. L. Mencken