Because the supposed army attacking had already turned around, as you were informed.
No, we weren't: not until just now.
And because the ruler of d'hara invited you to recon queer the ceded lands without intervention.
First Alanna's heard of it was the relayed message from Hireshmont to Malus just now. (And she's in almost all the Councils in LN, so if she hasn't heard about it, LN in general hasn't heard about it.)
Because every contact you've had with anyone in the moot has been them repeatedly repudiating any possible attack or plan to take lands.
IIRC, the 'moot in general had also advised against D'Hara including LV in their previous peace demands.
Because d'haran armies were already mobilizing against other foes.
It's easy to say that, but we had no proof.
I dunno, maybe every rational reason in the world.
Luria, at this point, honestly believes D'Hara to be deeply irrational.
You have to remember, we have just been through
months and
months of trying to convince D'Hara that
we are serious about wanting to fight Aurvandil, after destroying Luria Vesperi, and having D'Hara tell us, again and again, that we had to not only let LV live, but give them land, or protection, or special status or various other things.
It's all about perspective, Vellos.
Obviously from your perspective, a fellow member of the 'moot is trustworthy, and you can see the messages talking about how D'Hara wants peace, and wants the war to end.
We can't.
Literally everything that has come out of D'Hara over the past months has led us to believe they are paranoid, double-dealing idiots who have a vastly inflated opinion of themselves and would rather see Aurvandil conquer us all than admit that they couldn't defeat LN in a war. This incident plays
directly into those perceptions.
Do
not make the mistake of thinking LN is belligerent and irrational because of our perceptions of D'Hara.