I know history is doomed to repeat, but quite this quickly?

[Banquo's Ghost]

Well it's not that far fetched, why would Iran allow Iraq to become stable oil-producing power again if they can help it.

Because if Iraq retains its weak Shia majority government (so neatly installed by the US invasion) its oil effectively belongs to Iran.

Iran wants a Shia puppet government in Iraq. The insurgency is Sunni, and Americans are being killed by Sunnis. The Sunnis hate Iran.

If the Sunni insurgency is being armed externally, it is by Syria and Saudi Arabian interests in a desperate attempt to counter Shia ascendancy.

Iran is certainly meddling in Iraq, but it is to arm and strengthen the Shia militias that underpin al-Maliki's government. Even then they're not going too far, as al-Sadr for one is not particularly pro-Iranian. They want pliable puppets on the border, not heavily armed jihadists.

The invasion of Iraq was a dream come true for Iranian foreign policy. They have no interest in prolonging the US occupation, for the moment the Americans leave, they have a new oil-rich province and an ancient foe neutered. This is exactly what Bush senior was told the first time round - the difference being, he listened. This is exactly what the Iraq Study Group noted, and suggested it might be a good thing for this to happen with some degree of US input by negotiating with Iran.

Everybody knows it but Shrub.