Why do all empires gang up on the player in Birth of the Federation?
You can bend over backwards and keep ONE of them friendly, sometimes. But no, they'll attack you pretty quickly on most difficulty levels.
What I usually try to do is hunker in a corner, building up. Sometimes they'll give you enough space to get competitive. One time I did that though, and eventually emerged to find out that the Borg had taken over the entire Galaxy =P. They must have spawned right near me, and just expanded in the other direction.