Has The Post-9/11 TSA Done More Harm Than Good?

The Economist is debating the question. Bruce Schneier is against the changes:

Examining the recent failed plots against planes shows that it's not post-9/11 security that prevents terrorism, but instead pre-9/11 security. Consider the 2009 underwear bomber. Because security screened for obvious bombs, Umar Abdulmutallab had to construct a unreliable bomb. Instead of using a timer or a plunger or a normal detonation mechanism, he had to resort to an ad-hoc and much more inefficient system involving a syringe, 20 minutes in the lavatory and setting his pants on fire. Not only did the bomb fail to explode, but his actions were so obvious that the other passengers noticed what was going on and subdued him. The shoe bomber, Richard Reid, was foiled in the same way.

Kip Hawley counters:

There have and continue to be serious threats to aviation (and many other targets). TSA operations are required to stop the attacks in progress, for instance at checkpoints or with air marshals, but they also work with others throughout the American government and around the world to get ahead of future plots. "Airport security" is much more than the TSA and checkpoints; it has to be a connected network that links global intelligence, law enforcement, military and private-sector counter-terrorism resources.