Why do you think the Department of Homeland Security and the Transportation Safety Administration were created? That and a significant streamlining of the INS, and the most coordinated restructuring of all our top security and law enforcement agencies (CIA, FBI, etc) are the most sweeping changes of our top agencies in history. In a matter of 18 months they have gone from each one essentially operating on its own to a solid, well oiled operation. You bet we're fighting terror at home better than ever. The President is briefed on every single threat every day when he wakes up. All of them. Before his morning jog. We are more informed, prepared, and able to fight terror than ever before. While there may not be a 100% guarantee that we will never be attacked again, I would say there's a pretty good bet that nothing like 9/11 will happen again.

The fact that we haven't been attacked since is a testament to our prowess at home (and abroad).