The UK's Investigatory Powers Act Allows the State to Tell Lies in Court

Is it "rule of law" when the law is written to allow what would otherwise be unlawful?

This comes to mind every time I see something a news story about government malfeasance enshrined into law:

"The feeling will pervade the Galaxy that only what a man can grasp for himself at that moment will be of any account. Ambitious men will not wait and unscrupulous men will not hang back. By their every action they will hasten the decay of the worlds."

Though with the UK, another bit of writing applies equally well:

"That England, that was wont to conquer others, Hath made a shameful conquest of itself."

entropy