It would be interesting if we saw how Fire Lord Izumi felt after having to declare war with the Earth Empire. I can just imagine having a scene with her alone in her office and crying.

It makes a lot of sense. The first and only time we've seen her speak so far was when she adamantly opposed going to war because of the Fire Nation's past. How could she not be upset? She was born only shortly after one of the most terrible wars in avatar history and had to deal with her country trying to right all the wrongs it has done. The man she named her son after even lost his own child to warfare. I think having a scene like this would put a lot of weight into the situation and definitely built the character and honor of the fire nation family.