Apprehending them in advance isn't really what occurs, though. Rather, you spend billions of dollars putting up elaborate defenses against the previous successful plot. And you sacrifice as much liberty and privacy as possible in the name of anti-terrorism, but then you use your new powers for non-terrorism purposes.

I mean, look at the USA's terrorism laws. 99% of arrests from the TSA or the Patriot Act are related to things that had nothing to do with terrorism.

It's all just theater unless you can show that countries without that level of paranoia and invasiveness are getting attacked much more often. And I don't think that's the case.