Reply #82: Of course the president and vice-president don't

[rman]

design the plans, let alone execute them. But that does not exclude that they authorized it.
For planning and execution they have the agencies; see Bay of Pigs, Northwoods, Iran-Contra.

You don't need hundreds of thousands of people "all coordinating with one another". You don't need that in a non-secret large coordinated operation (such as war), nor is it needed if the operation is secret.
For instance in Iran-Contra, the pilots who did the actual drug-runs on Nigaragua probably knew they were participating in a larger sceme, but they did not need to know what it was.
The pilots did not need to be coordinated with everyone else who was participating, they only needed to get their orders about when to be where and who to contact. The rewards they received (primarily lots of money) and the fact that they knew what they were doing was illegal, was more then enough reason for them not to talk.