Why I haven't seen any muslim groups protesting over Paris' attacks as they did when some cartoonist published some cartoons about Muhammad?

Yes, you are correct. Those who do evil in the name of Allah are greater sinners. There are not more protests against Islamic terrorists because most Muslims fail to understand that these terrorists are actually causing great harm to Muslim communities throughout the world.

I would support any Muslim who volunteers to join in the fight against Muslim terrorists.

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.