Hey, I already praised this game in another post, but I still want to share my toughts on some additions that could be added.
I think a proper war system would fit the game perfectly;
With war, you're not able to expand onto other nation's territory, but you now have a "war" card to formally declare war on someone.
Once you're in war, you now can draw "war expand" cards just like the normal expands, but you can only alter the territory of whom you declared war on. To end a war, the attacker OR the defender has to draw a peace treaty card, which ends the conflict and sets the borders as they were drawn. Additionally, a war could also end when more than (for example) 10% of the territory was taken (not only from the defender. as the defender could pretty much turn the war over by drawing better cards).
Maybe while taking land in wars, the token land isn't represented by the attackers colour, but instead by the same colour in a lighter hue, to show the preogress of the war, which is then changed uppon peace.
Thanks for whoever takes the time to read this :D I really enjoy the game and think it has very very high potential, as of for now it is very addicting to play.
I hope yall doing well :)