[sudhirj]

The point is that public justifications are more important than actual motivations. Actual motivations can be enslaving other beings, ruling / mining an extra planet or just wanting to watch the universe burn. Motivations are already present because there are millions of motivations that map on to the same result - destruction of another group of living things. I'm pointing out that it's easy to find public justification as well.

It's also possible to do this unilaterally. China or any other country could also unilaterally decide to destroy another planet. And same possibility on the other side.

[ceejayoz]

Motivations lead to the justifications.

The problem with interstellar warfare is, outside the "Dark Forest" concept of "kill everyone just in case", there aren't all that many motivations that seem to make sense.

Any interstellar species probably doesn't really need to steal planets, resources, etc.

[chordalkeyboard]

If planets in the “goldilocks zone” are extremely rare and they want to “terraform” (xenoform?) those planets then thats a motivation.

[ceejayoz]

1. That seems very unlikely, from what we've found so far. We'll know more as things like the JWST come online, but right now it seems like planets of all sorts are everywhere.

2. Any civilization capable of interstellar travel is likely not to care all that much about a narrow band of natural habitability. They've already solved harder problems.

[chordalkeyboard]

I'm not sure its given that a civilization that has technology for interstellar travel is going to consider a planet that is suitable for life with little work to be roughly equivalent to a planet that is suitable for life with a lot of work. Its equally likely that they would be economical with their resources and consider a planet that is closer to the desired end state to be much more valuable than a planet that is much further from the end state.