A failed American attempt to abduct two senior Iranian security officers on an official visit to northern Iraq was the starting pistol for a crisis that 10 weeks later led to Iranians seizing 15 British sailors and Marines.
A story from the British paper The Independent accuses the U.S. of having precipitated the current hostage crisis where fifteen British sailors and personal are being held in Iran.
While the report must be viewed as merely speculative at this point, their appears to be enough first hand testimony to provide for a plausible scenario whereby american actions could have launched the current spat between these nations.