Here's a possible example:
Since we know the Zuma only take actions in response to what human players do or say to them, one possibility for the events is thus:
Madina, knowing that it would be fighting a civil war (from either sides perspective) decides that it doesn't want Terran interference in their war so that their side has a better chance of winning. This decision is made because the side expects Terran would side against them. Thus, this Madinan faction decides to give the Zuma 2000 bushels of food to invade Terran for a bit to make them wary about leaving their borders. The Zuma comply because for some unknown reason they need a lot of food for worthless regions. They make up some random excuse for the invasion and thus Terran gets attacked.
(This is purely 100% made up, although I guess it could be true, but is merely to illustrate that what someone thinks is going on isn't always the truth.)
Poll