I think the Bush administration is doing politics with the involved arab countries to back the ongoing reorganisation of the middle east. Maybe he needs something from them they don't like to cough up.
But I don't guess it's not about security of the Port - at least not immediately.
People have been screaming about others (mainly, the people against this) not having the facts but I have seen nothing in the way of facts or opinion that would make me support this deal.
The UAE may be our best ally in the Middle East but is that really saying anything?