If we are unable to establish some form of communication with others 'out there', there option of diplomatic advancement becomes extremely constrained. Hence, it is highly unlikely that we would be able to colonize any other planet.
If we assume that the population of Eden2 can be communicated with, then it is in our best interest to take a diplomatic approach. By virtue of our assumption that they may be more technologically advanced then Earth, it would be illogical for us to choose invasion. The odds are we would be stopped, or eliminated from existence. Either way we do not leave a good impression of our species with the population of Eden2. Alternatively they may have evolved a society that is non-violent or even pacifist; however, it would be illogical to think that they would not have defences of some sort, especially given their advancement in technology. For example, they may have an impenetrable barrier around the planet or their places of dwelling; or firepower that is activated by too close an approach to their planet or dwelling; or they may be able to disarm their foe by way of being able to phase-shift (i.e. become invisible). Hence, we would need to approach in a friendly manner, take a slightly submissive role as guests in their part of the galaxy who looking for somewhere to live.
We could assume that the population of Eden2 would want something in exchange for allowing us to colonize their planet, regardless of how friendly we are. As they may have more advanced technology it is unlikely that we would have much to offer in exchange. Alternatively,
They may want something from us that we do not want to give, which leaves a lot to the imagination and calls into question many other assumptions that are better elucidated in my next sci-fi book (assuming my first gets published!). However, the idea that another species would engage in Earth behaviours such as reciprocity, 'scratch my back I'll scratch yours', or 'survival of the fittest', is purely a human concept. As we are currently unable to, and most of us not interested in, communication with the myriad of species we now co-habit with, we are unable to conceive of different ways of negotiating or problem-solving. We have only our human perspective as the frame of reference from which to draw on, and so likely we are projecting our human concepts onto another species.
Given their probable higher levels of technology we could assume that they have advanced sociological systems as well, seeing as they have not used up all the natural resources on their planet, nor are nearing extermination of themselves through technology advancement. Although, from an Earth perspective, we have no evidence to support the assumption that advanced technology will ensures survival, given our present predicament. In the short-term, Earthlings can look forward to an extended life-span as compared to 100 years ago, thanks to technologic advancement. However, we also have decreased fertility rates and rising 'grey' populations in the West; overpopulation and appalling poverty in 'developing' nations; as well as mass species extinction and ecological breakdowns; pollution, depleted natural resources and global warming.
The evidence suggests that advancements in our technology will not ensure our survival.
Assuming that Eden2 has advanced socially, we could assume that they would be open to diplomatic negotiations regarding our colonization of their planet. Being socially advanced they would need to have ways of accommodating other