Even when I don't have the power to deal with it, I try to stick to the wording of my treaty, though. To me, it's a character thing...
Bear in mind that if you think about things on a suitably long term it becomes more important to keep to treaty terms. If you have major ambitions, people
have to trust your word, at least to a certain point, or you'll never get anything done. But the problem is there is
always a way around a treaty where you can claim you are justified, and if you win then your interpretation becomes predominant. Either you claim they weren't holding to the spirit or the terms, and produce suitable evidence to back it up, and you haven't broken your word. I've lost track of the number of times Jenred has done that, for instance, and the interesting thing is that he isn't lying. What he says is perfectly true, assuming his interpretation of events, and his point of view generally had a few thousand swords to back it up.
The more interesting trick is to know the people/realms/institutions you are dealing with, and how they interpret things. Make a treaty with, say, Riombara, and you'd better expect things to turn on the strict wording. Make a treaty with a Zonasan, and expect things to turn on the "honorable spirit" of the treaty. And often times it's even more complicated than that. Maybe you make a treaty with Ohnar West with Galiard leading it, but then Ohnar West goes through several upheavals, spawns Toupellon, then Toupellon collapses into Sorraine and Cathay, and you can pick up some of the bits of the treaty with Galiard, but the Ohnar West you originally signed the treaty with doesn't have any resemblance to the Ohnar West that exists now besides base geography and the name.
Or, maybe you make an alliance between Papania, Ohnar West, and Arcaea, where all three agree to help the other out in both defensive and offensive wars, but Ohnar West and Papania go to war over something that was Papania's fault but probably doesn't justify a war. Yeah, you
could have written a treaty to cover that, but no one would have dreamed it necessary because they were good friends...Then.
Everyone can always find generally true and probably legitimate ways of interpreting treaties how they need to, and they will be quite (genuinely, often) offended if you try to say they are breaking their word. They don't see it that way, because they are looking at the situation completely differently than you are. Treaties only work when you can get enough people on all the sides to
want them to work.
