As I've written time and again the Bush Administration's greatest failure was to tap the American public's post-9/11 reservoir of willingness; however, just enough of the American public stepped forward.The problem is, in some areas of the populace, the "reservoir of willingness" always was extremely shallow for solving the real problems that led to the unprovoked sneak attack on 9/11/01. The problem went way beyond just al-Qaeda and the Taliban. There were other countries who saw sponsoring terrorism as a very viable policy (like Saddam Hussein's regime). Some of them were/are developing weapons of mass destruction - and could have viewed groups like al-Qaeda as a very viable delivery system.
There is a vocal portion of the American populace that does not trust America's emergence as a hyperpower. This portion largely pushed itself away from the military by 1975. As I have discussed earlier, the military adapted, and emerged much stronger (it is amazing what happens when the personnel are not drafted, but instead are serving this country because it is something they believe in, and wish to excel at) as a result. The military is much more capable for its task of defending this country at this time - and does so despite the opposition of a small but vocal minority.
In essence, President Bush, Dick Cheney, Don Rumsfeld, Colin Powell, and everyone else involved in making the grand strategic decisions in 2001 knew that in some quarters, the reservoir of willingness to fight the war that needed to be fought was shallow, and only extended to doing part of the job that had to be done. The war on terror had to go beyond al-Qaeda and Afghanistan, but there was going to be resistance - some of it from inside this country. Look at the resistance to taking on Saddam Hussein's regime, despite the wholesale defiance of UN resolutions concerning Iraq's WMD programs and support of murder-suicide bombings by terrorism. Even the discovery of memos indicating that the regime had a relationship with al-Qaeda has not silenced people who claim the Administration misled the American people into liberating Iraq.
It is not as if they did not try to explain to the American people that this would be a long war that went beyond al-Qaeda. It is not as if they have not explained why they were viewing threats in a new light. A portion of the country (whose view is shared by major media outlets) has said, "We're not willing to take it that far." That's not President Bush's fault - that is the fault of those who have decided this country is not worth protecting, and a war for its survival is not worth winning.