How do you play both Entrenchment and Diplomacy?

Longtime Sins player here, but I lost touch with the series for a while after I got bored with the original and never bothered with Entrenchment. Tonight I bit the bullet and bought both Entrenchment and Diplomacy, but I'm surprised to see that they appear to be separate games--that is, they are launched separately either in-game or from Stardock. This begs the question--will I be able to play a game that has all of the features included in both expansions? That is, use both the advanced diplomacy system and build Starbases? Tried some Googling and checked the FAQs, but I haven't been able to figure this one out.