well at it themselves. The FBI should do cop things, the CIA should do intelligence collection and analysis stuff -- and two new agencies should have been created. One to do the counterspy / counter terror thing for and another for overseas direct action. None of those four things mix well with the others and you badly taint the ability and reputation of any one when you connect it with things it should not be doing.

Spy or Terr catching is dirty work and requires watching and waiting too often; Cops are intrinsically unable to do those two things. Anyone notice that most all the FBI terrorism related convictions entail a sting operation and the alleged perps are blithering idiots?

Using the CIA for DA exposes case officers to retaliation for things not their fault. It upsets the equilibrium and it causes dissension within the agency. The DA mission requires doers, the intel mission require thinkers. Yes, you can find people that can do both -- but not often. The CIA does not have a good record of catching its own spies, much less those from other places. Not their yob...

Unfortunately, given post Nixon, post Church Commission, post Carter and post 9/11 chances to better organize our assets; we instead continued to to bobble the punt. In the last case, we elected to create two massive bureaucracies to oversee the other Bureaucracies and changed nothing for the better. Sheesh.