They were a spy agency as long as they were the NSA, and inherited that function from prior, WWII spy agencies.
> That was the CIA's job.
CIA is a civilian spy agency focussed on HUMINT, analysis, and open source intelligence, and also the lead US spy agency (and it's head was essentially the overall head of intelligence prior to the separate DNI), while NSA has always been a defense department spy agency and the lead SIGINT spy agency.
> NSA were the security experts.
They have that function, too, but they have been a spy agency back to 1945 (before being public in 1952) and inherited duties from prior spy agencies when they were founded.
They were a spy agency as long as they were the NSA, and inherited that function from prior, WWII spy agencies.
> That was the CIA's job.
CIA is a civilian spy agency focussed on HUMINT, analysis, and open source intelligence, and also the lead US spy agency (and it's head was essentially the overall head of intelligence prior to the separate DNI), while NSA has always been a defense department spy agency and the lead SIGINT spy agency.
> NSA were the security experts.
They have that function, too, but they have been a spy agency back to 1945 (before being public in 1952) and inherited duties from prior spy agencies when they were founded.