The Arab world's problems are primarily a religious one between different Muslim factions. As such we should have and should keep out of it. Not only have we consistently screwed things up more by interfering, but we have also made enemies that we did not have before.
So far there have been 5 wars this century, all Middle East related. What have we got to show for it? Bin Laden was killed. There is civil war in Iraq, Libia, Syria, and undoubtedly Afghanistan when the final withdrawl there is completed. We have lost hundreds of military lives and spent untold billions in these wars. The end result seems to be chaos where none existed before to the same extent. The conclusion is obvious