If you think that, you are delusional.
Now, after we invaded in '03 and couldn't find the WMDs they started lying. Absolutely. But the basis for the war was incompetence.
Russia, France, and Germany seem to have much better intel, but we don't like listening to them. This seems to cross administration lines so it's not quite clear what the problem is (although that doesn't prevent a lot of speculation).
At what point does any sovereign nation that we disagree with become a threat because they have traditional munitions that we consider a WMD? At what point does having a 5gal gas can and a road flare in the back of a truck become a WMD... When ever enough of the public can be convinced of the new definition.
WMD was just a excuse, it was obvious to the entire rest of the world it was a lie.
From what I understand, most people believe that the invasion was instigated by Neoconservatives who believe(d) that the creation of a free democratic state in the Middle East would be a stabilizing force, which would be beneficial for US foreign/security policy.
WMD seems to be an excuse, but the true reason is well-intentioned (from a US point of view), albeit self-centered and naive. To think it had anything to do with the USD is a bit conspiracy theorist.
(Iraq did change reserve currencies from USD to EUR in 2001, however their total foreign reserves are $53b, not enough to spark a multi-year, trillion dollar war)
It is not a conpiracy theory, it is simple and obvious, many people outside US saw through the WMD accusation immediately, if everyone switched to buy oil with anything other than USD, US would be unable to print more money to keep getting indebted, and we all know that US currently has no way to sustain its economy without growing its debt.
It is just a matter of pre-emptive defense of domestic issues, the US cannot risk at all, even a minor risk, of other countries not allowing it anymore to generate loads of debt, because it depends deeply on it to sustain all its government spending.
Libya for example had the same kind of "protests" that turned into civil war, EVERY year, the only difference between the year they got a "no-fly" from others, is that Gadaffi also stopped selling oil for USD.
It is VERY CLEAR that US consider this a serious threat (and it is)
From some points of view, the government had no choice but to go to war...