If you look at it that way, you may say that the secession wasn’t successful. How can you rejoin something if you never successfully left it? In your post you said they weren’t fighting a foreign nation because the secession wasn’t successful. Just because the CSA only lasted a few years doesn’t mean they weren’t an enemy nation. The war wasn’t successful, but that doesn’t mean the secession wasn’t.

I defend a lot of these viewpoints because I like to argue. Also, I get tired of the hate towards these topics and the South in general sometimes. And finally, I view the topic differently than a lot of others. I hate the word treason and traitor due to the fact that I believe they became their own nation, however short, I hate that people assume the war was started over no reason, and I hate that people assume it was slavery when it is a lot more complicated than that. This includes things like “no it wasn’t states rights”, etc etc. It was about the states rights to make decisions for themselves. That included whether or not slavery should be allowed or limited. Nobody who reads history will deny that it was about slaves. But consider the economic impacts that something might have along with lifestyles that you have known forever and decreasing representative power (such as Lincoln getting elected with zero electoral votes in the south) and you realize there are many similarities between then and today. It was started because people wanted to do their own thing, and slavery was merely the biggest point of conflict in the fight to do what they wanted.