First Iranian President Mahmoud Ahmadinejad said that Iran was read to step into the vacuum when the US was forced out of Iraq. He oddly said that Iran’s friends, including Saudi Arabia, would help in this task. The hyper-Sunni Saudi government is actually not very friendly with Shiite Iran at all.
Then Bush rattled sabers against Iran putting the regime in Tehran on the same level as al-Qaeda as a threat to US interests. That seems a bit shrill.
Then US troops arrested 7 Iranians, mostly part of a delegation of the electricity ministry, but swiftly later released them.
The problem with the two leaders talking big against one another is that the provocations might suddenly get out of hand and suddenly there would be a war.