Honestly that cutscene prior to everything kicking off is probably one of my favorites in any game. It's a very simple and short exchange but you can just feel the underlying tension and anticipation of wondering what's going to happen next.
I picture everyone in Fleet Intelligence hanging on every word being spoken by the Kadeshi representative, while the ambassador ship sits there nervously as the Kadeshi ship slowly circles around him as he speaks. Then the words that have sealed the fate of this encounter are spoken: "If you will not join, then die."
At that moment everyone immediately realizes there is no way out of this encounter without having to fight for their lives. The ambassador ship sits there for a moment in stunned realization of this fact as the Kadeshi ship turns around to leave after casually announcing your imminent destruction. The ambassador ship finally turns to leave, the entire crew onboard with a pit in their stomach, wondering if after everything you have survived so far in the void, your journey finally ends here.
Meanwhile back in the mothership, the moment the conversation ended, everyone and everything is immediately scrambling to action. Everything is instantly at red alert. Fighter pilots and corvette crews immediately start preparing to launch as fast as the hangar bays will allow it, personnel on frigates start rushing to battle stations, and the commanders of all capital ships start watching with masked nervousness as dozens and dozens of fighters and frigates start pouring out of the large ship ahead in the distance. They aren't here yet, but they will be very shortly. Not even thirty seconds perhaps. The incredibly short calm before the storm, as many begin to make their peace with Sajuuk.
Then, all ever loving hell breaks loose as the last of your people begin the most savage and intense fight yet. The fight for their very existence.