Right now the only thing that happens when another Civ settles too close to your capital is you get a little bit of Influence. Thats it. If they have a large military presence near your borders though you can denounce the military presence. Wouldnt an option to denounce their expansion be warranted aswell?
#Can there be a way to diplomatically tell Civs to not settle near your borders?
thin flower
pulsar zealot
Josh go be with your new wife bro 😛 not playing Civ