[Valandil]

My position has always been "never attack anyone until they hve gobbled up eighteen nations and can eat you for breakfast," so maybe I'm not the most qualified judge here, but it seems to me that Zenphos should probably have either sought confirmation of the NAP or explicitly confirmed that no NAP existed.
If Zenphos is correct and he was deliberately seeking a war, using deliberately ambiguous wording and messaging strikes me as, though not oathbreaking per se, at least dishonest and deserving of a volley of seeking arrows.

How would the OP feel if his NAP proposal met with the response "maybe"?

That being said, ambiguous wording is not criminal, and better communication from the other party would have resolved this much more easily. I therefore reluctantly side with the OP, but suggest, without intention of giving offence, a less equivocal diplomatic methodology in the future.