Cui bono (iam)?

It's hard to decide what to make of a story like this:

(Reuters) - Afghan President Hamid Karzai intends to impose rules restricting international involvement in anti-corruption investigations, The Washington Post reported on Thursday.

The justification by the Afghan government is that the US government has de facto control over this body under current rules. I have no trouble believing that Karzai is absolutely corrupt and wants to shield himself, but I also have no trouble believing that the US government has control of the body and is using it to "influence" Karzai. I'll be interested to see where this story goes.