I remember when rulers were enforced by the honor code to only declare war if they had a worthy explanation for their hostility.
Enforced by whom? 'the honor code' is hardly chiseled into a stone tablet, and even when it is, political reality and chivalry rarely go together. Ohnar did screw up in letting Melehan sell food to Kindara. 'The honor code' could very easily be read to say that the realm should banish him. That has nothing to do with Sorraine but it reinforced the long-held idea of Ohnar West as a nest of vipers, even if Ingall has done a surprisingly good job in earning some goodwill.
I also haven't heard any realm accept Sorraine's casus bellus as legitimate. Sorraine is making a considerable gamble in banking on nobody caring enough about Ohnar to do anything about it. The question is whether Ohnar can capitalize on that in a meaningful way.
