This is by design. It will be cached since the underlying FlowDocument reference does not change. The solution is return the items not as a simple object but as a newly defined type.
Once you do this the values will come back via the arguments when the Compare command is executed.
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.