Too many variables, not enough observations

…or one thing I like about Barak Obama.

In an interview with Katie Couric last week, Obama made the mistake of giving an intelligent answer when asked about the apparent success of the surge. He notes that,

There is no doubt that the extraordinary work of our U.S. forces has contributed to a lessening of the violence, just as making sure that the Sadr militia stood down or the fact that the Sunni tribes decided to flip and work with us instead of with al-Qaeda - something that we hadn't anticipated happening. All those things have contributed to a reduction in violence.

You can add to this the fleeing of millions of Iraqi refugees, the success of ethnic cleansing in Baghdad and other areas that have lessened the need for sectarian violence, and the tacit support of Iran for Maliki’s government as evidenced by Iran’s intervention in Basra to settle violence there.

In short, Obama understands that while increased US forces may be one component of success, too much has occurred in Iraq in the past year to pin the reduction of violence (not elimination of violence) to the “surge.” Not only that, with Petraeus, the tactics used, down to where / how troops are deployed, have changed.

In science & social science, unless you can isolate your variables, you cannot definitely say what caused the dependent variable to occur. We have too many changes in Iraq to plausibly argue what the full cause of reduced violence has been.

In addition, Obama makes the better observation that even with the reduction of violence, maintaining troop levels in Iraq is extremely costly in dollar terms & military preparedness terms to the US, and the surge has not succeeded in one of its major goals – providing sufficient political space so that US troops could come home more rapidly.