re: Why do we need a CIA again?

We don't necessarily need the CIA but we do need some kind of organization that does what they are supposed to do. If this particular tree has too many elm bark beetles in it to be saved then we need to uproot it and replace it with a different tree and make sure that tree gets regular spraying (i.e. congressional oversight) to keep the beetles from killing it.

You can never have too much intelligence on China, North Korea, Iran, the Middle East in general, and Russia. Hell, given how some European nation's intelligence agencies played a part in the Steele dossier and the Mueller investigation keeping track of some of our allies may be in our best interest as well. However, someone has to be able to put a leash on them to make sure they are acting in our and our country's best interests and not in their best particular interests.