This is probably going to get super downvoted, possibly flagged, but what evidence does anyone have that they could not have stopped it?

I think it's PLAUSIBLE that the intelligence community knew and identified this attack ahead of time, and chose to ignore it.

I'm not saying that's what happened, but it wouldn't surprise me (let's be clear here: I'm not saying they caused it, I'm saying they knew and chose to do nothing).

That move 'The Imitation Game' raised a good point: If you have the ability to read 100% of your enemies comms...what's the best approach for defeating them?

The second you stop 100% of every attack you know about, the jig would be up, they'd know that their comms had been compromised, they'd switch to a different technology, and you'd be on the defensive (instead of offensive).

It's not like we'd even know how many they stopped, I'm sure that material is so classified not even analysts have access to it, let alone would it be open to FOIA requests.

Anyway, just a thought.