Since 9-11 the american government has used the tragic events as an excuse for acts that in reality has very little to do with fighting international terrorists, like invading Iraq.
No matter what the liar in the White House is saying, it is always done by military means, unless the administration is forced by circumstances to use other methods.
That is why you have american soldiers in the streets of Baghdad.
Now President Bush suggest that the military should take the lead role in responding to major natural disasters - according to this article on CNN.com
Maybe Katrina and Rita is just an excuse for bringing soldiers into the streets of american cities?