Since the Vatican City is a country, would you need your passports to enter?

No, there is no passport control for either. Tourists don't have access to some parts of the Vatican City, but you can visit St Peter's or the Vatican Museums without showing any documents. San Marino is inland from Rimini.

Most visitors just drive or take the bus; there's an arch over the road at the point where you enter San Marino, but no border checkpoint at all.

I know that I am not answering your question but if you are pressed for time while in Italy don't waste a lot of time going to San Marino. It is a picturesque setting with about a hundred knicknack shops and little else. If it is on your way while going somewhere else the detour could be worthwhile, but don't make a trip just to visit San Marino.

Passports not needed for either of these "independent" states.

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.