Of course, I am not imaginative enough to cover every type of relationship possible, so I will give you some pointers that might spawn ideas or let you figure it out for yourself, based on how each of these stand in your world.
1) Know the geography. Since I’m studying place in literature, I’m perhaps more sensitive to this than I should be. I don’t care. People and cultures are shaped by the places they reside in—and so are nations.
Do your nations lie across the sea from one another? Then they may have contact limited by the length of the voyage and the sophistication of the sailing technology, as well as by what drives them to seek each other out. (A trading voyage could be a reason to keep sending ships halfway around the world; the desire of one bored princess to see the sights would rank considerably lower). If they’re close to one another, separated by a strait or other small stretch of water, they may well be rivals, competing for the best fishing grounds and other resources, such as pearl beds and edible seaweed. If one is an island and the other isn’t, then the one that isn’t should take that into account for travel and invasion plans. Sailors who don’t know the island’s geography could be dashed to pieces on the rocks by the winds and waves, even if the human islanders would make them perfectly welcome.
But you’re not going to mess with that; your nations are on the same continent or island. Fine. There’ll still be issues with travel. If a mountain range separates them, what’s the best way of crossing it? Do both nations maintain a guard over it, and if not, why not? If a river’s their border, do guards patrol the river? How many different nations does the river flow through? Are there territorial disputes about it? Do the nations make claims to the same patches of land, even if the land is relatively useless, for the sake of looking powerful? If they’re friendly, what would happen if someone discovered a valuable commodity like gold (assuming gold is valuable in your world) right near the border? What happens if the border river becomes polluted? Negotiations and extradition could take on a whole new level when Country A wants to take and try Mage Marcus, a citizen of Country B, for his unwanted gift of a ton of dirty water.
How are borders set, for that matter? It would be best to affix them to some kind of point, either visible, such as a river or mountains, or symbolic, like a battlefield on which a legendary hero is said to have died. Or perhaps there’s a general no-mans-land, in which someone might reasonably claim to be a citizen of either country. Drawing lines out in the middle of nowhere and declaring them to be borders is more an exercise for cartographers back home, unless the nation has the soldiers to back it up and a reason—whatever it is—to claim this random field as their territory. (*gives David Eddings SUCH A KICK for all his randomly delineated countries*)
Perhaps the action takes place in a setting that’s not home ground for either of these countries, like a colony overseas that two empires would like to claim. Who has the better knowledge of how to survive there? Walking completely blind into new territory is asking for attacks by hostile natives, unknown weather, fearsome predators, savage diseases, and ordinary bad luck, like avalanches and dysentery. A nation which has taken the time to scout out the ground, befriend the natives, and shore up some defenses will almost certainly do better.
2) Know the recent history (not just the wars). Unless these nations are completely new to each other, the way that the Aztec Empire and the Spainards were, they’re likely to have some history. And yes, they can have fought before, and such a war can be poisoning the memory of everyone in Country A because those chickenshit bastards in Country B betrayed them to Country C, etc. But wars aren’t the only relationships possible:
-Armed truce. The countries watch each other warily, but don’t want outright war and won’t knowingly do things that would provoke it. (Who does, really? See point 4).
-High levels of tension. Perhaps Country A is picking off Country B’s merchants and anyone else who ventures into their nation.
-Deflected tension. Perhaps Country A normally has no reason to be afraid of Country B, but Country B is an ally of Country C, which is making threatening moves towards Country D, A’s ally. So, naturally, everyone’s sitting around on hot coals, and there are probably regrettable things happening.
-Situation-as-normal. Trade and immigration/emigration and travel by ordinary people are happening. This could come from a formal truce, but it doesn’t need to; perhaps the countries just don’t have many reasons to war with each other, and it’s been long enough since their last conflict that they’ve fallen into the habit of maintaining open borders.
-Opportunity-knocking. Country B suffers difficulties. Country A preys on it in small ways that won’t attract immediate hostile attention, such as by selling arms at a reduced price (but still pretty damn good) to its soldiers.
-Balance. Perhaps Country A has the advantage of cannons. On the other hand, Country B has mages who can make gunpowder explode with a glance, which kind of negates the advantage Country A has used to take over other nations. So both are sitting back on their haunches and scowling at each other, trying to figure out what to do, while both nations have their version of an arms race.
-Complete mystery. This works better if the nations are distant from each other and people from one don’t visit the other often, in which case all kinds of rumors probably spring up about what those pesky Dusk Country people are really up to.
-Superiority. Country B has conquered Country A and is mining it for all it’s worth. Country A fumes and plots. Country B laughs at them, or takes the plotting seriously and has soldiers occupying the towns.
It certainly helps to know the recent wars, but know what factors along with war have influenced trade, travel, weaponry, and the countries’ perceptions of each other. If nothing else, this will help you come up with strategies, tactics, and causes for the next war.
3) Know the language. Many authors do have carefully worked-out maps and backstories of their world. (Sometimes too carefully worked-out, as the author takes the chance mention of a character’s accent to tell you the history of his nation for five pages). But I think a linguistic history of the world would be helpful as well.
This is the point at which someone says, “I don’t need to have a linguistic history! My two countries speak the same language!”
And does everyone really speak the same language all over your world? (Shades of Robert Jordan!) I hope not. And even if your countries do speak the same language, it would be helpful to know the history of that tongue.
Helpful things to know for a linguistic history:
-Where the language originally spread from. This can help you trace migration patterns and the relationships of one culture to others.
-Some of its characteristics. I don’t think you need to work out a complete grammar; on the other hand, you could know its dominant sounds, and what its major differences are from any languages around it, so that you would know what a native speaker from a different area might find the hardest to learn about it.
-What languages it split into. If your two neighbor nations are sister cultures and speak sister languages, there are two obvious candidates right there.
-How it reacted to geographical barriers, or used them. A distant island nation might be the last place to hear the language of an empire. On the other hand, Basque speakers have managed to survive in the northern part of Spain for thousands of years, apparently since the original Roman conquest of the peninsula. (No one knows what other languages Basque is related to).
-What political differences it causes. Perhaps your neighbor nations do indeed speak the same language, but call it by different names to distinguish themselves. (Believe me, on the field of international politics, there are many, many things more insane than that). Perhaps a linguistic minority is holding out against a larger linguistic group—this certainly happens all over our world—and the language they speak is close enough to Country B’s language for them to make a claim on that government, or at least elements of that government, and possibly get some help. Perhaps Country A has thrown off Country B’s past conquest, but while Country B still ruled, it was made to speak their language, which leads to a violent prejudice against anyone with a Country B accent.
Fun, fun plots. Language is a tool of international politics in oh so many ways. Please don’t ignore it.
4) No stupid hand-tipping. I’ve complained about this before in political fantasy—and there, I was thinking more on the level of local politics or elements in just one court or country. When it comes to contests of power between nations, the rule’s even more applicable.
So this is Deldrie Greensnow, the emissary from, um, R’h’ellieth. (Do not try those apostrophes at home, kids). She’s been sent to the country of Whistanian to negotiate the return of R’h’ellieth’s crown prince, who got arrested for killing Whistanian’s Prime Minister while he was on a tour of that country. She knows that she’s going into a tense situation, where any false motion could result in not only her prince’s death but also an outbreak of war between Whistanian and R’h’ellieth. And, to make matters worse, it’s the late Prime Minister’s wife who’s come to greet her and escort her into their king’s presence.
Tell me, why does Deldrie always do something stupid like threaten the King, or mouth off to him, or take the Prime Minister’s wife hostage, or blurt out all her country’s plans to the first person who gets her drunk?
If you do want to play the game of international politics, and especially if you’re going to stir possible wars and arms races and murders and extraditions and other tense-making matters into the plot, please take it seriously. If you run into a plot problem, step back and work out what it would make most sense for your characters to do under the circumstances. Don’t try to “hurry the plot up” by having the nations’ ambassadors, heads of state, or other important people act like children on a playground. I’ve seen this again and again, apparently in the name of stupid prejudices like “all diplomats are slimy, swords are more honest” or stupid plans like “I’m breaking my writer’s block!” And the most common impression it gives is that the author was eager to get to the sword-fights.
If you want your characters to be trying to avoid war, have them avoid it instead of rushing towards it, hmmm?
5) Remember that other nations’ internal conflicts will still spill over their borders. Back to the situation in Point 3. The linguistic minority in Country A is being persecuted. Country B has a kinship to those people, speaking a language widely acknowledged to be almost the same, and the new Prince Consort of Country B has especially close ties to the minority, as his parents were immigrants from Country A. He starts agitating to do something. Meanwhile, other people, out of personal relationships with the linguistic minority, true goodness of heart, desire for political power, desire to crush Country A out of existence, and other reasons, are also agitating to do something. There have probably already been border skirmishes, and questions about what to do with refugees who are fleeing to Country B.
If I were the Queen, I would have a big-ass headache right about now.
Yes, war between countries is problematic. But it’s not the only problem, which is the reason all these points exist. Many, many international relationships between fantasy countries consist only of wars, with the occasional mention of a fat merchant getting skewered. That’s not good enough. Many authors also assume that if Country A starts having a rebellion, a famine, a plague, a civil war, or other internal trouble, it will mean nothing to Country B; in fact, they’ll probably sit on their fat asses and laugh. Why would they, when it can affect them?
Always keep an eye on the wider political picture. Even if you intend to keep all the action within Country A and won’t write a world-spanning epic, then you should be prepared to know what other nations will think of these problems, and how they will or will not get involved.
6) Decide what the concept of “nationhood” means. This goes at the end just because all the other points assumed that nations did exist in your world. And they do in a lot of fantasy worlds. And though I often bang my head against the wall in despair about the international relationships angle of it, I don’t think there’s a problem with countries as such.
But I think it would be an awful nice step in the world-building if authors decide what “nation” means.
Think about it. Nationhood comes out of a very specific kind of political rhetoric in our own world, which declared that if a group of people had a language, culture (whatever that meant) and ideals in common, plus they could settle on a certain piece of land that should be “theirs,” by golly, they were a nation. And if someone objected to that, by golly, the someone had to go.
Nations aren’t some kind of natural construct; nor are they entirely unproblematic. For example, India was not one nation before the British decided to come over and fashion it into one; its own people considered it a series of distinct regions and kingdoms, separated by religion, language, geography, and a whole host of other things. Without British interference, there might have been an eventual Indian nation, but there might also have been many smaller nations. Or not. It’s hard to say what “would” have happened without dipping into alternative history, but it is possible, I think, to say that the concept of “nation” got taken along and imposed whether or not it was wanted.
Think about the way the borders of the United States got fixed. A good deal of the US was once part of Mexico—in fact, was part of it until 1848, when the US decided it wanted that territory. After the war finished, a whole bunch of Mexican citizens suddenly learned they were part of the US. It wasn’t anything “natural.” It was conquest. Time can soften the memories, but it doesn’t mean that the US had any “right” to take the territory that it did, nor that if the borders of the US changed, it would be any more “wrong” than what’s currently there.
Even European nations could take their sweet time to coalesce. Both Italy and Germany remained a bunch of warring princedoms, or city-states, for a long, long time. Spain wasn’t a solid nation until 1492 in its current incarnation; the Moors invaded in 711 and drove the Christians to the north, while they established a southern country of their own called al-Andalus. When the Christians took the last Moorish kingdom, Grenada, then Spain was born, but al-Andalus died. (As a political entity, anyway; many Arabic words entered the Spanish language, and Arabic architecture, dances, and other remnants still survive, as does the name of “Andalusia” for part of the country).
In a fantasy world, history and geography and a thousand other things will of course be different. But be wary of imposing too pristine a history on it, of deciding that everyone just formed unproblematically into nations the moment they heard of the concept, and that countries should and will remain the same forever and ever, amen.
…Well, that was depressing.