If ransomware gangs are seen as a potential threat to national security, wouldn't preemptive action against these groups fall under the claimed remit of the NSA or CIA?

Tax evasion is a potential threat to national security, drugs are a potential threat to national security, protests are a potential threat to national security, q-anonsense is a potential threat to national security, especially when it culminates in an invasion of the Capitol.

You don't just get to sprinkle 'potential threat to national security' to turn criminal activity into a problem for the extra-judicial arms of your government. How about we let the police do their core competency - policing, and the military and the spooks to stick to their core competency - extra-judicial violence, and kidnapping random people to hold/torture without trial in Gitmo.

I'm not doing any such thing, hence the phrasing of my comment.

Your comment seems to imply you think the most/all of the remit of the CIA is or should be invalid. That position doesn't contradict my comment in any way.

That is a rather different claim than saying that premptively pursuing ransomware gangs in other countries is outside what the relevant decision makers view as the remit of the CIA. To me it seems to clearly fall in-line with their historic actions (as long as the cyber ransomers are outside of the country.)