pre-2001: Some bad dudes are busy cooking up a scheme to hijack airplanes and smash them into U.S. buildings. FBI agents in the Minnesota office report suspicions to their higher-ups in D.C. Incompetent/corrupt officials drop the ball.
Sep 2001: Dudes smash planes into WTC and Pentagon, killing nearly 3,000.
Oct 2001: U.S. invades Afghanistan, ostensibly to capture Osama Bin Laden.
2002: FBI threatens and intimidates agent who points out the agency's ineptitude (see above link). By year-end, 70 coalition troops and ~5000 Afghan civilians are dead. No sign of Osama.
March 2003: With the "War on Terror" in full swing, U.S. invades Iraq, ostensibly to seize weapons of mass destruction. Year-end: no sign of WMD.
2002-2009. TSA adds an array of security enhancements and travel restrictions. Cumulatively, more than 6,000 American deaths in war, hundreds of thousands of Afghan and Iraqi civilian deaths.
Dec 25, 2009. Umar Farouk Abdulmutallab boards a U.S.-bound plane with high explosives but in a fortunate fluke fails to detonate them.
Dec 27, 2009. Homeland Security Secretary Janet Napolitano: "One thing I'd like to point out is that the system worked."