The tension in the air was so thick it wouldn't be too farfetched to say that you could cut it with a blade, the disagreement between Rezar and the snow elf Queen could be looked at from a number of different angles and be judged in different manners. But ultimately the bottom line of their conflict would be that Rezar had never gone after her niece or her people of his own volition. Every action he had taken, no matter how brutal and merciless had been because they had gone after him first. This was no different from stirring a hornet's nest. He has been repeatedly provoked by snow elves, he would be a fool if he didn't retaliate.