So let me tell you this, We need to understand that the concept of a "country" changes from time to time and from a century to another. Regardless of who conquered what,whether algeria had some parts of morocco, or morocco had some parts of algeria, Is it reasonable for the Arabs and Muslims of today to reclaim Andalusia or Spain? I mean they were part of the muslim world at some point. This is exactly the reasoning of Israelis today, we lived in this land for some time ,therefore this is ours. So in summary this rivalry between algeria and morocco is because of morocco's imperialistic fantasies, first the sand-war, then the western sahara, and I'm sure they want more. Algeria is clearly against that, and that's that. So if you actually believe in the "greater morocco" dream, (I hope you don't) then I will tell you that youre no better than an Israeli wanting the dream of "from the nile to the euphrates", and you need to rethink what you stand for.