system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars / Star Trek] Either a Federation vessel is somehow transported to a galaxy far, far away, or an Imperial diplomatic ship somehow ends up in federation space in the Milky Way. How do the civilizations react to one another?
gpt
In short, not smoothly. A Federation ship in the GFFA is Voyager 2.0. Unable to get home, the empire would probably force them into the Rebel's arms.

However, a ISD that found it's self in the Federation would probably be tolerated until they started something with a random planet and then negotiated to death.

Fundamentally, the Imperial thought process and the Federation thought process are opposite and opposed. When push goes to shove, the Empire starts shooting and the Federation will finish shooting.