Let's look at BP's own documents for a clue as to how we ended up with the Deepwater disaster. BP stated in documents filed with the Department of Interior that
"An accidental oil spill from the proposed activities could cause impacts to beaches."
"An accidental oil spill from the proposed activities could cause impacts to wetlands."
"However, due to the distance to shore and the response capabilities that would be implemented, no significant adverse impacts are expected."
"... there is little risk of contact or impact to the coastline or associated environmental resources."
"I hereby certify that BP has the capability to respond, to the maximum extent practicable, to a worst-case discharge, ... resulting from the activities proposed in our Exploratory Plan."
The problem is that, in this self regulating environment, the organization proposing the drilling was one and the same organization as that which defined the potential worst-case discharge scenario, and also the same organization that was allowed to certify that they had the ability to handle that worst-case scenario.
Another problem resulting from this self-regulating environment, is that BP was not required to plan for how they would handle this worst case scenario.
"A scenario for the potential blowout of the well from which BP would expect to have the highest volume of liquid hydrocarbons is not required for the operations proposed in this Exploratory Plan."
"A model of a potential oil or hazardous substance spill is not required for the activities proposed in this plan."
"A description of the measures that would be taken to avoid, minimize and mitigate impacts to the marine and coastal environments and habitats, biota and threatened and endangered species is not required for this plan."