In 2000, Iraq switched away from selling oil for dollars, to selling oil for Euros. Then we went to war with Iraq.
Syria is trying to build a competing pipeline to oil to the European market. So we went to war in Syria.
In 2019, Venezuela and Iran created petro cryptocurrencies to use for oil trade. Now we're going to war with Iran. I suppose Venezuela was a little too close to home for an actual invasion, but we came close, didn't we?