So if it wasn't to maintain the status of the USD as the reserve currency which other reasons did the US have to invade? Apart from wanting to construct an oil pipeline through Iraq I'm not aware of any other reasons?
There is absolutely not a shred of evidence that the US has invaded anyone over the petrodollar.
It makes no sense in any geopolitical construct.
It's about on par with Obama being from Kenya.
Starting a war is a huge thing requiring a lot of political momentum, and almost nobody in the White House ever even knows what 'petrodollar' really is, they have no instinct for why it's important for America, and there are zero Treasury officials or folks from the Fed running around saying 'let's invade' over this or that.
The list of 'usual reasons' for invading Iraq and Libya are all in public domain by now - we know the things that Bush, Cheney, Obama etc. have talked about, we know their reasoning.
There is ZERO talk of petrodollar among them - ever - for any
reason, because it's irrelevant.
Military Generals sometimes fret about national security but there are ZERO instances wherein they'll talk about the petrodollar they have no idea even what it means.
The reason that most countries price in Oil is because it's very convenient to do so.
Do you think Saddam Hussein wants worthless Chinese RMB? What's he going to do with that currency? Send it to Germany to buy factory equipment? No. RMB is worthless outside of China. So what then? Pounds? Pesos? Aussie Dollars?
The only currency that could remotely be considered are Euros, but then, what's the point? Because USD are still superior and you're going to have to trade for them anyhow.
Yes, America gains somewhat from the petrodollar - and yes, they will lean on people and strong arm to keep people in check, but nobody has ever invaded anyone over currency pricing.