How different is “Be rid of somebody” from “Get rid of somebody”? Are they interchangeable?

Question

In the movie review article of Clint Eastwood’s “J. Edgar” in the New Yorker magazine (November 14) titled “the Man in Charge,” there was the following sentence:

“A single scene with Robert F. Kennedy in the early sixties, when, as Attorney General, he was Hoover’s boss—stands in for Hoover’s relations with the various Presidents who longed to be rid of him but didn’t dare show him the door. Hoover tells Kennedy that he has evidence of his brother’s sexual escapades with dubious women, and his job remains intact.”

I noticed the writer (David Demby) used the phrase “various Presidents longed to “be rid of” Hoover,” instead of “get rid of” Hoover and show him the door.

As I checked the difference of meaning between “be rid of” and “get rid of” with a dictionary at hand (Sanseido’s The Wisdom Dictionary), it defines “be rid of” as “be released from nuisance / trouble,” and “get rid of” as “remove (expel) nuisance / trouble.”

Oxford Dictionary also defines “get rid of” as “take action so as to be free” and “be rid of” as “be freed or relieved of.”

If the above definitions apply to the above quote, “be rid of” sounds oddly passive, inactive, and somewhat derogative to a president’s authority to me, and I wonder why the most powerful man in America needed to mercifully “be rid of” one of his mere subordinates, not “get rid of” him to show the door, if he found his subordinate a grave obstacle to his governance, no matter how the latter brandishes his power.

Did the author intend to say all presidents who had dealt with Hoover were bound hand and foot by Hoover for almost 50 years and wished simply to "be rid of"?

Is it improper to use “get rid of,” instead of “be rid of” Hoover?

Answer 1

They are not interchangeable, and Denby uses it for a reason. The reason is that if he said "get rid of" it makes the president sound less human and more criminal. Using "be rid of" sounds more reasonable for a president who is bound by law and by politics. Usually, "get rid of" is used for something other than a person: get rid of lice, get rid of trash, etc. If used by a person in power, then it implies foul or violent means. "Be rid of", as you guessed, implies something a little more passive, but that's not necessarily weak or wrong.

Answer 2

"Get rid of" means "do something to remove an annoyance".

"Be rid of" means "no longer experience an annoyance": this might be by one's own act, but it might be by somebody else's act or by chance. (It might also be by one's covert act, not admitted).

Answer 3

For a president to "get rid of" Hoover would have been to take positive steps to remove him, thereby subjecting the president to whatever payback or vengeance Hoover may have cared to unleash (which, we can assume, would have been substantial; Hoover supposedly had enough 'dirt' (incriminating information) on just about anybody in power that he could have gotten them removed from office by revealing it). So, getting rid of Hoover would have meant having him get rid of you in return. Nobody was willing to pay that price, so the presidents instead longed to "be rid of him", i.e. to have someone else take the actions and pay the price, while they (the presidents) reaped the benefits of having him gone.