One would think balkanizing what Arabs themselves consider to be Arabs is less likely to produce stability in the region. Using my head doesn't leave me enamored of a bridge to the 12th century.
In fact, 19th nationalism was based on recovering a common identity for Germans and Italians in the past. In the case of Germany, the king of Prussia comissioned a German history and German music.
In this instance, however, you might be thinking that it would be best for everyone to bow to Mecca in more ways than one. Yet Saudi ambitious of Wahabism is often linked to fanatical terrorism. I am not at all sure that the Saudi monarchy should extend its tyranny. An EU federation that respects differences is probably better, though the strong common influence of Islam is sure to continue.
We do not have any right to impose stability and oppression on people out of our own indifference and desire to be done with their problems.