Considering that all you really need is fission bombs and the will to do it (ie project Orion in the 60's) we could be an interstellar civilization now (specifi

Considering that all you really need is fission bombs and the will to do it (ie project Orion in the 60's) we could be an interstellar civilization now (specifically, I'm talking about nuclear pulse propulsion generation ships). So if a civilization at about our tech level could dedicate a few decades of global GDP to building the infrastructure, one might ask, what goal would motivate such an endeavor? There are many lofty, high minded goals one could consider; exploration, discovery, species/ecosphere survival in the face of an imminent global threat. Finding, enslaving, or eliminating other sentient life forms? I can't see how this could be the goal of any civilization. Maybe the same impulse that could lead to organizing such an incredible, global effort to build the interstellar infrastructure in the first place could also dictate this less savory motives, ie religious zealotry ie Church of Galactic Subjugation. The above is speaking to a possible interstellar civilization and not much more than our tech level.