Who wants to tell me about the Xi'an?

The Xi'an are a very long-lived civilization. They walk around on two legs. They have a very long history. Our first contact with the Xi'an was kind of a public relations disaster and a diplomatic disaster, because a terraforming company back in the Messer era, when everybody didn't really care about things like rights to terraforming planets, moved in and started the terraforming process, but they didn't know that it already had Xi'an on it. So that led to a horrific encounter where the Xi'an, naturally not trusting all these people who are shooting lasers at their planet, took them hostage. And that's how the Cold War between humans and aliens started.