We aren’t.
No organized army is going to die to keep any part of this nation from seceding that has the popular support to do so.
Any leftist city that wants to bolt, then go for it! That fuel and food you are going to need in order to not die will be sold to you just like it’s sold to any other 3rd world nation that can pay.
Civil war does not necessarily equate to secession. In fact, most of the civil wars in history had nothing to do with secession.