I don't know. The shia sunni split existed long before the US ever came into existence as a nation. And the problems they have there now may be exacerbated by the US being there, but under Saddam the shia suffered quite a bit.
The shias and the Kurds suffered in Iraq under Saddam during war times. And there were high conflicts between the two religious sectors some time ago but in modern history there wasn’t that much tension until the United States decided to topple the Iraqi government.
Conversations With History: Iran, Israel and U.S. Great interview with the author of Treacherous Alliance: The Secret Dealings of Israel, Iran, and the United States [youtube]Ly0sUxYgL8M[/youtube]
Secret dealings of Israel, Iran and USA? Well, that explains Ahmadinejad's threat to wipe out the "Zionists" (how he was quoted) and the Iranian support of Hizbollah & Hamas... C'mon, who believes in such fairy-tales?
I didn't want to comment again in this thread but yet another comment that shouldn't be made. This is not to say there is definitely some secret dealings going on, but you're dismissing it because of the tension between the sides?? Don't forget that the tension at times seems to be very useful for all involved (even if a few of the bystanders get the shit end of the stick). A simplified example would be 1984's concept of the 3 superpowers who were at war with one and allied with the other at any one time to ensure what they wanted to achieve was achieved internally!!
I completely agree. I disagreed with some of his points but his analysis of the geopolitical changes brought on by the Gulf War (1991) and the end of the Cold War in the same year is spot-on. He does discuss in detail why Israel, via AIPAC, supported US arms sales to Iran in the midst of the Iran-Iraq War, when US had just finished dealing with the hostage crisis.