Explained here. A taste:

But if Eikenberry is the interlocutor for the day-to-day and Clinton is the interlocutor for the biggest crises, then Holbrooke’s interlocutory role is rather less than clear, and now Karzai knows that if he doesn’t like what Holbrooke tells him, he gets a second bite at the apple with Clinton. Perhaps Holbrooke’s more durable role in the administration is to coordinate the interagency team that he’s assembled to get diplomacy, development work, intelligence, communications and finance for Afghanistan and Pakistan all rowing in the same direction. But wait! If Stuart Bowen’s proposal for a new U.S. Office of Contingency Operations goes forward — and a formalized proposal for it is coming very soon — Holbrooke will lose that role as well. So where would that leave Holbrooke, the premiere diplomat of his generation?