The government had no ability to stop the leak, but the whole scenerio could have been prevented had the regulations been enforced. This is the deepest well ever drilled in the Gulf. BP had no plans as to how to deal with a possible explosion or any kind of complications with a well that deep, but the officials in charge of regulating these wells allowed them to drill anyway.
Remember, "Drill, Baby, Drill!!!!"?
That's why we have a disaster in the Gulf that has changed the invironment and a way of life there forever.