Well, in these discussions, I'm sometimes minded back to Eddington likening the Federation to the borg. Eddington's lament was that the Federation does a sleight of hand whereas the borg are up front about their conquests. Now that's obvious hyperbole and trolling of Sisko and what have you. But there is a kernel of truth to it too.
The Federation likes to decorate all of its institutions including Starfleet as being devoted to science, exploration and peace. And this ethos once established then entices members to join the club. That -- and colonisation projects -- is the method by which the Federation expands whereas most other imperial rivals seem to expand by brute force. In this sense, Starfleet is there to defend territory already gained. It doesn't want war not just because they are a swell bunch of guys but also because war actually undermines their ability to expand.
What I'm trying to say, is that the Federation conquers not through force but through its ethos. And Starfleet is on hand to hold territory once gained and guard against adversaries. That's a military role as well but it's not something that Starfleet likes to formally prioritise despite it being defacto what they do. They want to keep their ethos as devout altruists intact for public consumption and because thinking in these terms has a therapeutic influence on them too.
The Federation likes to decorate all of its institutions including Starfleet as being devoted to science, exploration and peace. And this ethos once established then entices members to join the club. That -- and colonisation projects -- is the method by which the Federation expands whereas most other imperial rivals seem to expand by brute force. In this sense, Starfleet is there to defend territory already gained. It doesn't want war not just because they are a swell bunch of guys but also because war actually undermines their ability to expand.
What I'm trying to say, is that the Federation conquers not through force but through its ethos. And Starfleet is on hand to hold territory once gained and guard against adversaries. That's a military role as well but it's not something that Starfleet likes to formally prioritise despite it being defacto what they do. They want to keep their ethos as devout altruists intact for public consumption and because thinking in these terms has a therapeutic influence on them too.