@flavius, on Jan 13 2007, 09:40 AM, said in International Relations and Galactic Politics:
Systems of three states, which are quite common in sci-fi, are really quite unstable unless one state is overwhelmingly powerful or weak enough that the it is irrelevant. Otherwise, two would gang up on the remaining state and destroy it.
Actually, on reflection, I don't agree with this conclusion.
First of all, it doesn't follow directly from the (very reasonable) points listed above it. It may be that it is possible to conclude it from them, but you haven't demonstrated how.
Now, considered on its own merits, is it true that in a system of three states, two will always 'gang up on' and eliminate one? It's very hard to find examples in world history, because there is always an outside force which comes into play to stop there from being any 'pure' system of three (or any other number) of states.
One example that does spring to mind is that of the Balkan Wars (1912-13). In these, first of all an alliance of Bulgaria, Serbia, Greece and Montenegro defeated the Ottoman Empire, conquering Macedonia, Albania and Thrace. A Bulgarian army was even within sight of the walls of Constantinople. However, the allies then fell out. In essence, the Greeks and Serbs thought that Bulgaria had gained much more from the war than they had, felt threatened, and allied against Bulgaria. As Bulgaria suffered defeats, the Ottomans got involved again, reclaiming most of Thrace, and so did Romania. (The results of this war are the main reason why Bulgaria is such a small country today. Had things worked out a little differently, it could easily have much more extensive territory in what is today Macedonia, Turkey and Romania, and an Aegean coastline.)
What did not happen was that the allies 'destroyed' Bulgaria completely. In fact, as soon as Bulgaria was reduced to a state of weakness again, the temporary allies became far more worried about each other again. Of course, the next 'Balkan War' - in which Serbia, Greece and Romania would be on the opposite side from Bulgaria and the Ottomans - is better known as World War One …
So, that's one reason why - in a system of three states - two would not necessarily gang up on and destroy the third: as soon as the two states gain an advantageous position, they become more worried about one another than their defeated enemy.
Another reason is time. Over the course of history, wars have moved at quite different speeds. If the Balkan Wars had been fought with late- rather than early-20th century technology, in the First Balkan War Constantinople might have fallen to Bulgarian panzers before the Serbs or Greeks had the chance to stab them in the back. A scenario designer is free to speculate about just how quickly or slowly interstellar warfare might move.
Along with time comes money. It might be true that if two powers ganged up on the third they would win: but how long would it take, and how much would it cost? If the whole process takes decades - or centuries - then it is likely to be a series of wars rather than one continuous one. And every outbreak of peace between wars is an opportunity for the pattern of alliances to shift. Or for technological change to transform the whole dynamic of the war. (Or, for that matter, for domestic political change to alter things.)
Finally, the idea that a system of three states will always become a system of two states implies a view more broadly that the number of states in a system will always grow smaller: five to four, four to three, three to two, and the final two to battle it out till just one is left.
At the end of the 19th century, this view might have made a lot of sense. More and more parts of the world had fallen under the control of a fairly small number of powers (mostly European). Perhaps the clash of powers was just a giant game of conkers? However, by the present day this process has gone completely into reverse, such that it's hard to give it any credit: there are far more states in the world today than there were just twenty years ago. And the prospect in the future is only for more states, not fewer: for instance, the prospect of Scotland leaving the United Kingdom is in the news at the moment. Kurdistan, anyone? Catalunya?
The key area in which you're right, however, is that it is worth a designer thinking about this kind of question.
This post has been edited by pac : 13 January 2007 - 10:53 AM