Re: Have we (the US) screwed up the Middle East?
Want to be specific?
How about fleshing that out. Be specific, please.
In essence it's all about oil and you'll kill for it. Right?
1. I tried to address these in sequence.
We haven't been "constantly screwing" with the 'people' and 'governments' of the region. The vast bulk of the regimes in the Middle East either predated US involvement and/or have come about as a result of indigenous movements. I struggle to think of a country who's borders we 'determined' other than Iraq when we drove them out of Kuwait. We've assassinated vanishingly few Middle Eastern leaders or heads of state. In fact I'm struggling to think of any that we did. Would you care to name some that you think we killed? The selection of 'new heads of state' has also been vanishingly rare if not non-existent. The only example that comes to mind might be Iran but that doesn't really fit with your description.
We've certainly played both sides of the field in certain circumstances. This is only reasonable when you are presented with two terrible choices. The alternating support for Iraq and Iran during the Iran-Iraq War was emblematic of our desire that neither Baathist Iraq nor Islamist Iran would become hegemons in the Middle East.
Obviously US companies, like Dutch, British, Chinese, Korean, Japanese, etc, etc, companies have invested in the region and have periodically been given state partnerships as a result of their technical expertise, especially in the 50's and 60's. This has largely abated in favor of more conventional FDI. When have we sent our missionaries to assist with propagating our 'national religions'? We've occupied one state: Iraq. I hardly care about the 'sovereignty' that a genocidal fascist dictator asserts. Etc, etc, etc.
2. Without US involvement in the Middle East we could point to a plethora of likely outcomes. Going to the immediate post-war period in 1946, it is likely that without US pressure the Soviet Union would likely not have withdrawn support from the Mahabad Republic which would have likely resulted in the creation of a Sovietiezed Kurdish 'Republic' protruding into Iran as a springboard for deeper Soviet penetration and further conflict. This is just one early example among a litany. Without US involvement in the Middle East it is likely that Saddam Hussein and Baathist fascism would reign from the Euphrates to the Gulf and that his government would once again have become embroiled in a war with Iran, a war, with new resources, it might have won. Without US involvement it seems quite likely that Jordan would have collapsed in bloodbaths under pressure from Syrian backed Palestinian uprisings in the 1970's. Without US involvement it seems probable that the Soviet Union would have extended an immensely greater hand throughout the region ensuring much greater regional conflict and violence between the likes of Soviet backed Syria and Egypt against Jordan and Iraq. Instead, as a result of US involvement, these conflicts never materialized and remained 'cold' before eventually dissipating.
I mean I could go on and on. The list of hypotheticals is nearly endless.
3. You wouldn't? Civilization hinges upon access to resources. Food, Oil, Water, Copper, Rubber, it doesn't really matter what you call it. There is a difference between advocating Imperial conquest and colonization and recognizing the importance of resources and the need to ensure that they do not fall into the wrong hands. I'm perfectly willing to say it was in the interests of the United States, and the world, that the oil and natural gas of the Persian Gulf did not fall under the exclusive control of Saddam Hussein.