The Arabian Peninsula is a one of the harshest places on the planet, and this has served very well for the people living in here as a protection from invaders. This peninsula is almost totally covered by deserts. There are extremely high temperatures, and also strong winds that create deadly sandstorms. There isn't any river that has water throughout the whole year, and also the food resources are very scarce. All of this made it very unattractive for any invaders for starters, and also as a great protective barrier, which led to a partial isolation of the people in this region.