Terrorist attacks are by an large unavoidable when this country's foreign policy for the last seven years consisted mostly of creating as many terrorists as possible. Convservatives' inability to understand that bombing a man's house, killing his family, and/or detaining him for years without charge, especially in a culture in which these violations of honor demand retribution, are going to create immense numbers of terrorists never ceases to amaze me.
Obama could increase the the size of the US military and intelligence budgets tenfold and there's still no chance that all terrorist plots would be foiled. The only logical course going forward is to stop creating new terrorists and take sensible precautions for preventing what we can and dealing with the inevitable attacks that slip through by those that we've already created.
For those of you conservatives who only listened to Rev. Wright's "God damn America" soundbite out of context, that was the point of the sermon it came from. 9/11 didn't happen because Al Qaeda "hates us for our freedom." It happened because the US has spent the last fifty or so years fucking the middle east up.