Morrus, correct me if I'm wrong and please do, but it seems to me you think that because we can't do something now we can't do it ever.
No, he isn't. He's arguing that we could not do it now, assuming a reasonable time of discovery in the past. What happens in the future is the future.
Umbran, I think, made the assumption that they are humanoid but what if they are a hive-mind type of aliens? Have you ever tried to have a conversation with an ant colony? Note, a drunken monologue doesn't count. You get nothing but a swath of red bumps and burning skin from that.
Cue Ender's Game and the Bugger Wars? Per previous post, really not relevant. They cannot actually use our planet at the time under consideration, and we couldn't really use theirs. The only reason to go to war is fear that the other guy will, but the other guy has no reason to go to war!
This is where the interplanetary scenario differs from our Cold War. Our Cold War was ultimately over (proxy) control of real-world resources that could be used. The Russians presented a threat of taking over Europe and Asia, because they could have *used* Europe and Asia. At the tech level cited, the Martians have no use for Earth. We have no use for Mars.
We can only think of going to Mars to use it now because it is uncontested, and even then the economics make it a questionable venture. Make it so before you can get anything out of it, you have to demolish the planet, it becomes even less attractive.
We will find ways to kill things if need be.*
Yes. My point is about the lack of need.
I'm quite positive that while we try to communicate and understand each other, running parallel to this endeavor will be individual militaries or global collaborations commissioning research into information gathering and weapons technology.
Yes. So, let us think about that for a moment. How, exactly, are you going to test whatever weapons you develop? You sure as heck can't test them on Earth.