I will agree that agencies such as the NSA, DIA, CIA & FBI were not as hindered prior to "The Wall". However, the Military Services themselves WERE very much hindered in investigating US Persons - especially domestic, but also foreign!
This was more due to the military infiltration of subversive student organisations in the 60's and early 70's than it was FISA & Co.
FISA and all subsequent legislation & EO's merely reinforced the already existing barrier bewteen the military and the civilian departments.
I grant that NSA & DIA are technically "military", but they are separate from, say US Army Counterintelligence. This is my point. AD was a truely military operation (apparently with some contractor involvment). The DoD lawyers, rightly or wrongly concluded that ATTA & Co. were "US Persons" and this alone was sufficient to shut down AD and cause all records to be destroyed. The Chinese aspect just adds another twist to the whole bloody mess. AD *might* have been able to get away with the investigation *if* prior approval had been obtained from the AG. However, the hurdles involved in getting approval for such were very high, and, most likely, if approved, the operation would have been conducted by NSA / the FBI - according to the powers that be, the military itself investigating "US Persons" is just not kosher.
So it wasn't the Gorelick Wall between intelligence and law enforcement, nor even the politicization of the OIPR door in that wall by Scruggs and Gorelick, that killed Able Danger. Rather it was another (albeit similar) wall entirely - the military vs domestic wall.
Dang - we are going to have to be careful in uncovering this. Well, Congressman Weldon is going to have to be careful. It would be altogether too easy to make an inaccurate claim, or even to be distorted by the Left and the Main Stream Media into seeming to have made an inaccurate claim. Either way, that would be quickly followed by being discredited.
It's a field of landmines. And the enemy is more than happy to partially expose one mine, in order to entice those of us who are too eager to step on another and blow our foot off.