Strictly speaking, if someone is said to be Jewish, does that refer to their religion or their nationality?

Both. And for all that it doesn't seem like a satisfactory answer, that's just how it is. It doesn't even really matter if you're Orthodox, Conservative, or Reform, so don't worry about trying to distinguish among them if you don't know the difference.

"Nationality" is a recent invention. Forgive me, but I'm going to discard that word because it doesn't fit here. Let's look at it in terms of "ethnicity" or "ancestry" instead, because those terms are more readily applicable to ancient history.

-- Judaism is a religion. Jews believe in God, they follow His rules from the Old Testament (okay, some follow more than others, but the 10 Commandments are pretty standard!), they have certain prayers that they make in certain situations. And you can convert to Judaism.

There are no Jewish missionaries. They won't go looking for converts, but if you prove that you're serious and you really want to be Jewish you can do it. Some people may be more welcoming than others, but converts to Judaism ... more.

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.