but I got intrigued by the idea of Iran's president Ahmadinejad that the US wanted the documents to be published/leaked
The guy runs that talking point since Wikileaks revealed Iran's involvement into Iraq.
Getting this out in the open probably weakened Iran's overall diplomatic position in the world, now that other countries that might not like Iran know that even Iran's neighbors are preparing for war with them.
"Even Iran's neighbors"? Of course those countries who suffer under Iran's power approve of the war.
Every decently informed government also already knew that Saudi Arabia was upping it's military.
As far of actually thinking that the US has a motive to create such a leak, no they don't.
The US doesn't want the that Arab governments get destabilized because the population of those countries knows that the government cooperates with the US.
You also shouldn't underrate the amount of trust that gets lost when French politicians, German politicians, Russian politicians etc read what the US wrote about them. Julian Assange and the Computer Conspiracy; ?To destroy this invisible government? zunguzungu
is worth reading to understand what the game is Wikileaks plays is about.