Keep Your Friends Close and Your Enemies Closer? Why Would I Keep My Enemies Close?

[AFTT47]

Where is the sense in that?

Others have already answered this but I'll put it in my own words:

It's desirable to keep your enemies close because it's easier to see what they're up to that way. If you keep them fortressed away, you won't have any idea what they're scheming.

At least that's the way it works in dramatic fiction. I don't know how it works in real life because unfortunately, I'm not important enough to be concerned about enemies plotting nefarious schemes behind my back. Nobody pays that close attention to me.

Of course, that's just the way I want it! Bwahahahaha!