Does Demacia expand it's borders?

I know that they are not a power hungry empire like Noxus, and much like pre WW2 America, they all much stay out of foreign wars, unless they menace their borders. But re-reading Lux backstory, it comes to mention some "contested lands" that acted as "buffer states" between them and Noxus. It makes me imagine that, even when technically they have a defensive foreign policy, in similar way to the pre war U.S.A., they do have interest in, if not annexing, making sure that lesser kingdoms close to their borders have governments in pro of their interests. But thinking in how feudalism works, and in how Demacia is basically a feudal society, it's probable that these lands get annexed to Demacia as a kingdom in the long run via political marriages, and fights for the heritage of these regions. They are a very old and very powerful kingdom in the military sense. So, even while not being like Noxus, it's hard to imagine their kingdom not taking any chances to expand their borders and their resources. Because, again, U.S.A. made the same with regions like Cuba, Puerto Rico and the Philipines. Hell, you could even put as an example half of their states in continental North America. So, maybe, even if not as big as Noxus, theirs is a bigger state that we imagine thanks to how the lore presents it. What do you think?