My soon to be xwifes sister, who grew up in Iran, had a good take on why a US "puppet" govt will be doomed to failure in the mid east... its got everything to do with the epic failures of US "meddling" in the region, our pals Israel, and the genuine hatred for the US govt that' has resulted.
Some examples of US "meddling" from her POV which failed on many levels:
In 1953 the CIA helped overthrow the Iranian Prime Minister, installed the Shah and helped start SAVAK, which she called "Iranian gestapo"... who were trained by the CIA and were just as brutal as Saddam's dudes, if not worse. People were rounded up, jailed, tortured, killed and the blame lay squarely on the United States shoulders as far as the "resistance" was concerned.
The Shah was a spectacular failure of US foreign policy, resulting in Khomeini taking power after the people revolted against the US "puppet", stormed the US embassy, held hostages and all that.
Since then the US is referred to as "the Great Satan" in Iran, scarier than the boogie man... untold numbers of Iranians have been rounded up, jailed and or vanished for being spies of "The Great Satan", once again the US Govt to blame as far as many are concerned. They're basically paranoid about more possible US interference and take brutal measures to keep The Great Satan out.
Khomeini taking over, that really got us perturbed, so we crawled into bed with Saddam Hussein, you know the big bad WMD guy, armed, informed and funded him... he attacks Iran with our full support. Apparently its "well known" by people in the mid east that we were fully aware Saddam used US satellite intel to gas Iranian troops... which is why "many" in Iran see supplying IED / weapons to Iraq enemy fighters is seen as "payback" and they support it.
Of course to the Iranians the Iraq Vs Iran war is just another US orchestrated attack on Iran's sovereignty by "The great Satan", millions end up dead.
For generations now Arab Muslims, Persian Christians, Sunnies and she-ites have supported their brethren against "The Great Satans" tremendous screw ups across border lines... from Saudi, Syria, Egypt..
So far, in the past 50+ years, as far as a great many people in the region are concerned, the US has done nothing but damage in the mid east, while being best friends with Israel, Saddam and the Shah.
As they see it now, when trying to manipulate Iran failed miserably, we moved next door to Iraq, and what a fantastic job we've done there making friends.
With all this history of failed US policy in the region, with the US always backing the wrong guy (Shah / Saddam) leading to unmitigated disaster, and our close ties with the "Zionists".. why will a US "puppet" govt will be tolerated today? hatred for US policy has been around for generations and lots of people are more than willing to go kill US troops to avange family members killed the in Iran / Iraq war, jailed, tortured, murdered.