As far as I know, the clip I need does not exist on the Internet.  So, you will have to do with a description instead.  In an episode that begins with a bear roaming the streets of Springfield, the townspeople demand that the mayor institute a wide-reaching bear patrol that includes vans and helicopters. 

Homer: Not a bear in sight.  The Bear Patrol must be working like a 
       charm.
 Lisa: That's specious reasoning, Dad.
Homer: Thank you, dear.
 Lisa: By your logic I could claim that this rock keeps tigers away.
Homer: Oh, how does it work?
 Lisa: It doesn't work.
Homer: Uh-huh.
 Lisa: It's just a stupid rock.
Homer: Uh-huh.
 Lisa: But I don't see any tigers around, do you?
        [Homer thinks about it, then pulls out some money]
Homer: Lisa, I want to buy your rock.

Now imagine that Homer was later mauled by a tiger.  Would this be proof that the rock did not work, or proof that the rock was in fact more vital than ever? And what the hell am I bringing up a 10-year-old Simpson episode for?

Replace "rock" with "Guantanamo Bay" and "tiger" with "terrorists" and you pretty much have this story.

"The emergence of a former Guantánamo Bay detainee as the deputy leader of Al Qaeda's Yemeni branch has underscored the potential complications in carrying out the executive order President Obama signed Thursday that the detention center be shut down within a year."

Despite all the torture and various and sundry shady activities of the last 8 years, we managed to capture and release this guy.  So instead of meaning that the anti-terror policies of the Bush administration were failures, it means we actually need to continue them?

 Lisa: That's specious reasoning, Dad.

My thought exactly.

(Tip via Joe)