If so, do you feel that you are able to actually help improve humanity or reduce threats to humanity and the planet we depend on?
And if so, would you encourage anyone else to apply?
I think working for intelligence agencies, especially taking technical work (think sigint, encryption/descryption, malware/malware defense, etc.) is very, very interesting, but improving humanity is a huge burden that no agency can shoulder.
On the other side, I think someone mentioned that the work of the intelligence agencies is not to prevent wars, but to prevent world wars (not exactly what he said but I believe it is what he meant). From that perspective, they are "helping" humanity.
There’s your answer.
It would be nice, though, to feel that there was something we could do to right the many wrongs in the world. As it is, it seems that any individual effort is pointless. Collective effort is not pointless, but it seems like throwing masses of human fodder to slow the evil enemy. Maybe eventually the enemy runs out of energy or will or actual lifespan.
Meanwhile, I miss the old Matt Damon. And I'm angry that he did not have enough good acting opportunities. He's one of my top five favorites.
In other words, not just code breaking, but code making (and other facets of security).
Of course, the NSA has also been caught a few times deliberately weakening the security of US communications in order to give themselves an edge in decryption when COTS products are used by adversaries (betting that no one else would be able to make use of the same weaknesses), but there are other agencies that aren't quite as… conflicted (eg. CISA).