ISA was born out of sheer necessity when the CIA was looking after its own interests, not giving two damns about the military SOF's mandate. In order for them to fulfill their given objectives, JSOC needed their own unit that could gather tactically-relevant intel & prepare the ground for SOF insertion.
But I don't see our ops being subject to this kind of conflict of interest anytime soon. If the military is pursuing an op, it'd be as per the wishes of the Govt, and our intel agencies neither have the intention nor the b@lls to go against the Govt in pursuit of agencies' own view of national interest.
Ironically ISA works now extremely closely with Delta and DevGru developed Black Sqd for the same task.
Both ISA and Black have a very evolved mission with includes urban UC operations. That's why the closest we have is the SG.
Task Force Orange (ISA) also now includes their Civvie air support. I have read an account of delta and ISA stage an operation from the border of a friendly country where little birds were driven in trucks till the border. Assembled for flight. They flew overland to hit their target and then flew back. The trucks then loaded the little birds and drove back to their waiting C17 at the airport.
ISA had infiltrated the target country seperately and exfiled seperately, did the target reccee and provided sniper and overwatch. Delta flew in and out on the little birds.
The whole time the friendly country didn't know what was happening. All they knew was that a US C17 was parked on their runway to transport some stuff for the US embassy.
One of the best SOF stories of the modern age I have read