Dr. Clam said...
You can't avoid (3) without tearing up the Constitution and jumping up and down on the pieces. The United States still operates on a Federal system, to a much greater extent than Australia, and the states concerned in particular have a long tradition of telling the Federal government to bugger off and leave them alone, to the extent of being reduced to rubble over it. Normally this decentralisation of power is a good thing: in this particular case it was a bad thing. But a counterfactual that says 'don't inolve the states' is as silly as a counterfactual that says 'send in the cloned super-soldier penguins to rescue survivors'.
This is the whole point of "State of Emergency". Emergency powers have been abused in some countries, it's true; however, surely there are provisions for it in the US constitution. Levee breach in New Orleans = temporary suspension of decentralisation of power, just as I would hope it would have been had Cyclone Katrina hit us after Sid.
Incidentally, I have seen research regarding storm surges, and the figure was, any particular point on the tropical East coast of Aus gets a storm surge of average 4 m once in every three hundred years, based on geological time scales.