Having either an adversarial system or constitutional court doesn&#x27;t stop a government from using its power to do illegal, immoral, secretive, or plainly unconstitutional things.<p>Historically, and across pretty much every nation that has ever existed, governments have routinely chosen to disobey their own laws, do terrible things in secret, and so on.<p>I also fail to see how a constitutional court prevents FISA from existing if you have executive orders and national security doctrine (the two things that made FISA and the NSA spying possible). You&#x27;d need to throw out a lot of things to make a constitutional court work. As it is, national security doctrine would simply bypass a constitutional court check when it comes to creating FISA. You would have to try to elevate it above all possible counter considerations, and good luck with that.