The geographical importance of Iran as far as the Western Empire is concerned is also material and just as important as it sitting on all of that oil. Turkey and Iran are key to flanking Russia from the south which would allow Military force projection into Central Asia.
Recently the EU member nations signed an article condemning China building its “silk road project” across Central Asia as they claimed it would give China an unacceptable competitive advantage. Iran is to be a linchpin in that project. Iran borders all of the “Stans” in the underbelly of Eurasia and China along with Russia in promoting the Silk Road project will gain significant influence in that region.
Military force projection is about controlling resources AND access to the same and these resources include everything from Oil and Natural gas to Copper and Iron ore. One reason why North Korea has a right to fear the US military is it has an abundance of metals and other resources as yet unexploited. One reason why China and Russia both seem to side with North Korea is they know full well that if the North Korean regime falls, US troops will be close behind to occupy that nation bringing them right to the borders of Russia and China in that region as well.
History has shown that once the US sends in troops into a country they become an all but permanent presence and infrastructure projects to support the same soon follow. This followup of Military spending then ties the Nation in which it occurs to the Western Empire as a revenue stream.