[Suicide Junkie]

I changed the final mission settings to activate the next campaign as P&N instead of regular, so all you should need is to be running the very latest Version of campaign 1 when you visit the terran contact for the Last time and the "next campaign" button lights up. At least, that's my theory.

Check to ensure the Last lines in the main_events.txt read:
Number of Results := 1
Result 1 Type := Go To Next Campaign
Result 1 Param 1 := P&N - Border Wars