okay you would risk your men and resources in a war where there is expected to be a long winter? You would send your men on the battle field instead of fighting a war where you lose no men, no resources and lets say you win, you now have less men are open to an attack from some other house or whitewalkers, if you lose, you lost your lands and family, i would take a quick painless win than a long war. Honor is winning and writing your own history. Yes i violated a trust, be oaths and treaties are broken every day, even Dany, she could traded her dragon for more of the unsullied and walked away, did she? No she took her dragon back and sacked the city, honorable? No but smart, she gained gold, and a free army.