Respectfully, anyone who “knows anything about the ME” would completely disagree.
For starters, the Iranian government is lots of things but it is most certainly not “a fundamentalist Shia regime” and in fact is hated by fundamentalist Shia.
Moreover, anyone familiar with the ME would certainly know that Iran has repeatedly allied itself with “fanatical Sunni organizations” when it was in their interest to do so. The most obvious being Hamas, but they were also willing, according to several reports to aid various Kurdish groups against Saddam Hussein.
Beyond that, since you refer to “basic common sense”, according to “basic common sense” does the Iranian government hate Salafists more than it hates the US(AKA the Great Satan) and Israel(AKA the Zionist Regime or The Jews)?
I ask because we all know the answer and Iran regularly collaborated with both the American government and the Israelis throughout the 80s and the early 90s, prior to Saddam Hussein getting defanged during the First Gulf War, when it was in their interest to.
For those interested, I’d highly recommend The Treacherous Alliance: The Secret Dealings of Israel, Iran, and the United States, by Trita Parsi, President of the National Iranian American Council.
http://www.amazon.com/Treacherous-Alliance-Secret-Dealings-Israel/dp/0300143117/ref=sr_1_2?ie=UTF8&qid=1347944964&sr=8-2&keywords=Trita+Parsi
I’m sure some are thinking of the phrase “The enemy of my enemy is my friend” but in truth, from the Middle Eastern perspective, a better saying would be “My enemies are sometimes my allies”.
Nor is it just the Iranians for whom this is true.
King Hussein attempted to invade and destroy Israel in 1967, but he and Israel regularly collaborated in secret decades before he finally recognized Israel and Israel offered him some protection against moves by both the Syrian and Iraqi Ba’athist governments.
Nor, would anyone dispute that Lehi hated the Nazis, but they were more than happy to collaborate with them during WWII against the British(though the Nazis rejected them).
Beyond that, I don’t see why the idea of Iran collaborating with Al Quaeda would be more preposterous than the idea of Israel collaborating with Hamas, but in fact they initially did because they saw them as a good check on Al-Fatah.
Like I said, the Middle East is vastly more complicated than westerners think and much of what might be seen as “common sense” to westerners are simply flawed assumptions.