Boundaries are not threats. They are boundaries. Threats are not boundaries, they are threats.
Boundary: "I will not stay in a sexless marriage."
Threat: "If you don't give me more sex, I'm getting out of this marriage."
You may argue that the 'or else' is implied in a boundary. Depends on who is listening, I guess. All a boundary does is state what you will/won't do. It does not DICTATE another person's actions in the least. The other person is, always, free to choose.
Think of a "No Trespassing Violators Will Be Prosecuted" sign. I'm sure you've seen them before. I suppose you could call that a threat. To me, it is a clear indication of a boundary. It is NOT a threat. It is a promise.
