Well, you're in prime position to turtle up and reach for the stars. That would be a solid, sure win, if a little dull. The "foreign influence" seems to be mostly crap cities that are only good for keeping the Barbarians at bay and offering up choice targets for your Spies, but I can see the appeal of keeping your continent "clean." Maybe compromise? Conduct a quick "war of purification" for some laughs, then get down to the serious business of shipbuilding?