Analogy time.

It appears the current American security is similar to car alarms. You can't stop the car thief, all you can do is make it hard enough to make the thief want to go to the next car. Yet you're not going to prevent the knowledgeable, skilled, and motivated thief, they will get your car, one way or the other. You just put up enough challenges to the thief that they go somewhere else to steal. Or you own a car that doesn't provide anything they want. Or you accept your car will be stolen, and make appropriate plans.

Sometimes, you'd think this mode isn't to stop or catch the aggressor, it's to scare them away.