That's not to say we shouldn't take measures to stop terrorism.  Absolutely, we should.  It would be unjust and foolish not to do so.  But we must take reasonable measures, and it doesn't seem like much of a stretch to me to say that looking into possible motives for this terrorism (and not just the motives we want to be true) is going to be a more productive activity than simply making ridiculous but ineffective airport security measures more ridiculous.  As Glenn Greenwald explains,

to discuss causes of Terrorism is not to imply justification; one can seek to understand what we do to fuel Terrorism without suggesting that the deliberate targeting of innocent civilians is in any way legitimate or justified.

Read the rest of his piece here.