So what do you propose we do? Hm?
Terran has only sold small amounts of food very sporadically, and only when we felt it was necessary for our survival. I guess maybe Asylon is selling tons of food. But, again, what do you propose we do? Attack Asylon because they're helping the Zuma? I don't think the Zuma would like that, for some reason. Madina sold food... and the Zuma are no threat to Madina.
The problem here is that a trader could come over all the way from, say, Morek, and sell food to the Zuma, and thus strengthen them against the Moot. And there is no "Arrest trader" option to my knowledge.
Again, one or two nobles operating secretly, quietly, or even accidentally could set off the chain reaction with food that makes the Zuma "Too big to fight."
Attack the Player realms because they are feeding potential enemies? Yes, absolutely. Perhaps that is one of the reasons the Zuma are there? To cause contention between player realms so that the game remains interesting?
You can't say for sure that the Zuma would do anything about you attacking Asylon because you haven't tried it. My personal opinion is they would do all of nothing about it. Especially if you made the smart decision to create a reason for war that completely ignored the Zuma. If they are at war, they can't possibly continue to sell food because you'll be burning their food stores. At the end of the war you can make terms of conditions that any food surplus they have MUST be sold only to Terran or kept in surplus.
There, you've accomplished keeping the Zuma weak, while never letting on that's what you were doing.
As far as operating secretly and selling the Zuma food, I find that hard to actually accomplish until this new trade system was produced. How is a trader going to explain a journey into Zuma lands, when he has to pass through or around your realm to reach them?
Truthfully though, this whole conversation is starting to bore me because it seems no one is even interested in trying to figure out what makes the Zuma tick. They have a set of rules to follow and their actions betray what those rules are if you pay attention closely. I know its been said that ppl don't care to try and figure out the Zuma at all, then they don't have to do that either. You CAN pretty much ignore the Zuma if you want to, especially if you don't choose to stay right next to them. As far as I can tell, aside from some random threats, the Zuma have done no more dmg to any realm on Dwilight that random monster and undead attacks haven't done to realms. In fact, while the Zuma have destroyed zero realms, rogue spawns have destroyed multiple realms of Dwilight. If your realm was destroyed by the Zuma with no reason given, then sure get upset. If they attack your army and decimate it once or twice and you "maybe" lose a single region, there is really no reason to complain, especially when in recent days your ruler has begun to purposefully annoy the Zuma.
The Zuma have a driving force behind them, and stuff they rely on to make them strong. I'm not going to give it away, because aside from an OOC perspective that I think that ruins the game, from an IC perspective I like Luria knowing more about the Zuma's intents than those who would possibly interfere with Luria if they were free to do so.