Crab,
I want you to put this disaster into perspective....try to imagine the entire land area of the UK....all 94,000 square miles of it (approximately)....with 500,000 (or more) homeless and/or displaced persons.....with the entire area....all of it...without electricity, telephones, drinking water....roads blocked, bridges down, railways blocked, bridges down, airports closed due to all of the above....no fuel or very limited fuel supplies.
Now, respond to all of that...and get round to everyone....remembering the evacuation of New Orleans did not take place per the official Emergency Preparedness Plan. How long does it take to mobilze 40,000 troops and get the logistics train set up....establish on site bases for operation...get fuel, food, and tentage established.