Would you rather...

• Learn of authorities foiling a terrorist attack here in America or against American interests, or
  
  
• Not hear of anything (whether nothing happens or something got foiled) and keep wondering...

Either way supposes that there was not a successful attack. While the former shows the success of our security measures, it proves the terrorists are still actively trying to hit us. With the latter you might have no idea if security is working or not but at least you are not aware of anything.

I'm not sure if "ignorance is bliss" trumps "well-informed but worried" here.

Me, I'd like to go to sleep and wake up something next week.