I think I'd let them complain, they could do a few other things if they didn't want to participate but gees! Christmas is for kids and if the kids wanted a house full of streamers and glitter then that's what I'd do. You never know, they might get into the spirit of things later, I just wouldn't bother too much and do what I and the kids wanted to do.... and bah HumBug to them :).
Tell him it's what the kids want and he should at least make an effort for them. Then go about decorating while he is watching and thinking over what you said. He might come around or he might not either way I would try to make it enjoyable for the kids.
Just try not to overwhelm him with it all. Maybe bake some cookies and decorate the house a little, but for god's sake don't play any music. Nothing pisses me off like the music.
Try to work out a compromise with him.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.