We had a perfectly suitable reason for declaring war. We just sucked at the execution.
Let's face it, the two sides of a war will never agree on whether the other side was justified in dedclaring war. But in this game, we need to sieze upon even the smallest reasons to start a conflict and keep the wars going. Ohnar West undermining the war effort against Kindara by selling them food, when the northern realm's strategy was to starve Kindara into submission, was far from a small reason.