If only it were that simple. Disband the FBI, the CIA, sure. But what do you do with the personnel? Line them up a wall and shoot them? They’ll still be around, only now they’ll be free agents, with no checks and balances whatever. They can make trouble all they want, so long as they don’t get caught. Start a new agency, sure. Staffed with whom? Old FBI ex-agents? How will you train the new agents? At Quantico?
But what do you with the personnel?>>>>>>>>>>>>
You retire as many as you can......you vet some to be trainers, and you send the rest to be retrained to serve
as military intelligence agents.Inside military command, they step out of line and the get court martailled or dead.
A very few would be transferred to the new agency.