That never happened, and that assertion was simply another in a long list of lies put out by the MSM and the LA and nat'l Democrat politicians as part of their efforts to smear the Bush administration and deflect attention away from their own incompetence and unpreparedness.
While it is a "fact" that a lot of National Guard were busy in Iraq (and still are), the assertion that this caused a shortage of Guard personnel and resources for Katrina relief was a flat-out lie. The reason there were delays in getting Guard resources involved was that LA Gov. Kathleen Blanco refused to give her okay, as required by law, despite repeated urgings from President Bush.
In fairness, however, Bush bears the full blame for failing or refusing to publicly call her on it. For whatever reason, that failure of command and leadership on his part allowed her and the MSM to win the PR battle and convince the American public that Bush and his administration were primarily to blame for all the aid debacles of Katrina.
As subsequent history shows, the Katrina episode, and many other examples of his mind-boggling inability or refusal to recognize that there are certain enemies who must be confronted and defeated rather than placated and appeased, has cost him, and us, dearly.
http://www.click2houston.com/video/17492630/index.html
For anyone who’s interested- here’s a fascinating 30 minute walking tour of Galveston done by one of the local news reporters- shows the high water lines on the Strand, Post Office etc. (roughtly 7-8 ft)
The island behind the sewwall fared a great deal better than anywhere else.