Seeking the Power Position

Stratfor has a good but not great track record at reading international crises. So read this with caution. But they do add to the landscape by interpreting Iranian/US relations in the context of the active diplomacy that is going on presently - diplomacy that few in the US want to recognize for the obvious reason that it doesn't fit with the anti-Bush meme (ie Bush ignores Baker-Hamilton).

In any case, this is the core of their reasoning:

...the Iranians have sent two signals.

The first was that while the United States is concentrating its forces in Baghdad and Anbar province, Iran remains perfectly capable of whipping up a crisis in the relatively quiet south-where U.S. troops are not present and where the British, who already have established a timeline for withdrawal, might not have sufficient force to contain a crisis. If the United States had to inject forces into the south at this point, they would have to come from other regions of Iraq or from the already strained reserve forces in the United States. The Iranians are indicating that they can create some serious political and military problems for the United States if Washington becomes aggressive.

The second is a statement about the negotiations over Iraq. While they are interested in reaching a comprehensive settlement over Iraq, the Iranians are prepared to contemplate another outcome, in which Iraq fragments into regional entities and the Iranians dominate the Shiite south. In some ways, this is more than an acceptable alternative. For one thing, in holding the south, the Iranians would be in a position to impede or cut U.S. lines of supply running from Kuwait to central Iraq. Second, their forces would be in a position to bring pressure to bear on Saudi Arabia, unless the United States were to redeploy troops.

In other words, the shift of attention to the south poses a worrisome military challenge to the Americans. If the Iranians or Shia were to get aggressive in the south, the United States could be forced to spread its troops even thinner, leaving operations in the north severely weakened. The maneuver could help to collapse the Americans' position in Iraq by overloading them with responsibilities.

Read the whole thing to get the proper context, which is that both the US and Iran are seeking to position themselves well in present negotiations.

Update: The above analysis would seem to be confirmed by yesterday's first roadside bomb deaths in or around Basra.