Ultimately Iraq 2 was all about oil, because Iraq 1 was all about oil. And if it wasn't for Iraq 1 Saddam would still be America's Middle East Poodle to this day and Iraq 2 would never have happened. Don't forget that most of the attorcities committed by Saddam that were listed as a reason to bring about regime change were pre-Gulf war 1 when America and Iraq were on friendly terms making common cause against Iran. And recall that Iraq didn't make it's own chemical weapons, and it wasn't about to get them from Russia, who was helping Iran in it's military efforts because... well because Iraq was being supported by America. It was always a somewhat fraught relationship, especially given Saddam couldn't be too pal-y with America because of the whole Israel thing. But so long as Iraq (and most of the Sunni world - though recall that Iraq is Shiite majority, but was ruled under Saddam (who's Baath Party is actually secular socialist) under the guise being a minority Sunni tyrant - had issues with Shiite Iran and containing it's regional aspirations, and Iran was a common enemy between US and the Sunni nations they could justify staying reasonably close and Israel remaning a bit of a sore point that could be dealth with "later". Though the Arabs from an ethnic perspective don't have a lot of time, or sympathy, for the ethnic Palestinians - so it's not just about religion.
But Saddam wanted Kuwait's oil wealth (possibly because he was running the country into debt so needed another source of state revenue) and he used a flimsy claim that Kuwait was historically part of Iraq as a pretext for invading and taking control of the oil (there's absolutely no other reason to invade Kuwait). Bush Snr probably would have let that one go, but for the extremel.y negative global reaction to the Iraq invasion and the clamouring to kick Saddam's army out that couldn't be ignored. So Bush Snr came reluctantly to war, but once he was committed he needed to at least see Saddam beaten back. In truth a contained Saddam was the better option, though some wanted him gone, and they survived the Clinton years to make it into the Bush II Whitehouse.
War is only really fought for 1 reason: resources. Whether it be the basic resources of land on which to live, or the value of the stuff that can be found in or under the land. And always the power that comes with having control over resources. Whether it's to take more resources or keep the resources you have. Sometimes there's an ideological angle to a war, but it's still about resources underneath it all.
So given wars are always about resources, what's the resource behind the Iraq wars? Dates? Sand?
Please also remember that the Taliban AND Osama Bin Laden were originally supported by the USA when it was Russia who were trying to own Afghanistan. OBL only really turned on the USA when, after Gulf War 1, the USA established permanent army bases in Saudi Arabia (sure it was at the bidding of the Saudi monarchy, but OBL doesn't like them either).
Then you have to go all the way back to World War I to see how the Ottoman Empire was carved up after the Turks backed the wrong warhorse in siding with Germany (kinda ironic that Germany now doesn't want Turkey in the EU). USA and Britain shared the middle eastern (oil) spoils between them (Hello BP! which used to be called the Anglo-Persian Oil Company, who, soon after WWI, struck a mother of an oil find in, guess where...Iraq), and created these unnatural nations, shoving a bunch of people together as a single nation, not realising that simply because "they all looked the same" they weren't the same and in fact there were deep ethnic and religious divisions. The country now known as Iraq had never existed as a nation ever in recorded history until after WW1, in fact it really only became defined by its current boundaries in 1926. Iraq (or a small part of it at least) is where the first known civilisation began and where writing (and hence the creation of an historical record), was born with the Sumerian civilisation.
So, was the latest Iraq war about oil? When in the last century has any upheaval in the Middle East NOT been about oil?