Some members of the Federation I'm in temporarily usurped my position as President by summoning dimensional fleets to inflate their fleet power. When they downscaled their fleets later (I assume their economies can't sustain it since their Naval Capacity is lower) and I regained presidency, I find out that apparently they trapped all the ships in an isolated system with no hyperlanes. Nice one guys...
This is how I found out that I can actually engage Emergency FTL outside of combat (by pressing the Return command without any valid path).