2. This creates built in demand for Dollars
3. This amounts to a free lunch for the U.S., which has led (among other factors) to our spending money like there is no tomorrow.
4. Iraq, under sanctions, and with the U.S. especially making it hard to make ends meet, attempted to make separate deals with other countries to sell oil in other currencies, thus obviating the need to buy U.S. currency first.
5. Purely by coincidence, our invasion of Iraq scuttled those plans.
6. If trading in oil in other currencies became commonplace, the value of the U.S. dollar, and the need to prop up the U.S. economy, would spiral down to a less artificial level. In short, the U.S. government would be put on an enforced starvation diet and the economy of the U.S. would crash to some (unknown, but probably epic) degree.
7. We suddenly find that the Iranians (who might have a bit of trouble with the dollar, given the current sanctions and resultant tensions) are working on nuclear weapons whilst simultaneously making arrangements with several countries to sell them oil without using U.S.D.
Yes, it will. Just like the Titanic sank even with the pumps going wide open, just a little bit later. Would the fact that she was going down anyway have made YOU shut the pumps off if YOU were the captain?then it will collapse sooner or later. Thus war can only postpone temporarily that collapse.
You haven't taken any economics classes yet, have you?So instead of war abroad maybe US should think of strengthening its currency?