There is apparently a law from the 1920's that prohibits foreign countries shipping from stopping in more than 1 port. That is some of the regulatory hold up with the "help" from outside the US. Seems someone could issue an executive order or something to dispense with the holdup.
BP is 41% owned by British concerns. A lot of people in Britian would be hurt (and already are) by a collapse of the company. Likewise in this country (USA) because 39% of the company is owned here by regular folks who own mutual funds in their 401ks/IRA's that hold BP stock. Cutting off our nose to spite our face?

The nice part about being a pessimist is that you are constantly being either proven right or pleasantly surprised. - George Will
"It's not that liberals aren't smart, it's just that so much of what they know isn't so" -Ronald Reagan