The group of peoples known as Arabs existed long before the birth of Islam. They didn't suddenly appear from nowhere! In ancient times the Hebrews were just one of these peoples and did not stand out for any particular difference. The exile of the city population to Babylon changed this and when they returned they had no land, so they established a trading community which spread all over Europe and North Africa and beyond, long before the destruction of Jerusalem. Their religion became important to them as a way of holding together this community. This is what made them different; it wasn't a racial difference. Nowadays a lot of Jews don't look like Arabs because they recruited people from the countries where they lived, in spite of their claims about racial purity. That explains why European Jews look European, Ethiopian Jews are black, etc. Of course each nation writes its own history, but it's absurd to make big distinctions between the Jews and the Arabs of thousands of years ago. They were the same people.