The fact of the matter is the Vietnam Dong and Iraqi Dinar are in no way tied together or linked together. It can be argued Vietnams economy and even currency value is linked to that of China and even Japan. That is true. The Vietnam Dong is not however tied to the Iraqi Dinar, their economies in no way hinge on each other and their economies and currencies have nothing to do with one another.
The only common link between the Iraqi Dinar and Vietnam Dong is that speculators who "invest" in one often "invest" in the other. That is the only similarity or tie between these two currencies.