So what if Israel and the Arab world go to war?

These are the basics:

Israel vs Arabs

-Egypt
-Syria
-Saudi Arabia
-Iran
-Jordan
-Other Arab allies not directly involved

-The US, UK, France, Iraq and other NATO/Western Allies will support Israel

-Russia, Yemen, North Korea and other anti-NATO/anti-Western Allies will support the Arabs

Who will win?

  I would agree with James.  There are such deep divisions between the various Muslim groups that it would be hard to see them fighting on the same side, even if the Israelis say started mass deporting of Palestinians from the west bank and Gaza.  The Saudis and Iran hate each other and it would take a lot to see Egypt and Jordan dragged into such a conflict basically on the Russia/extremist side.

  Also I would be doubtful that western powers other than the US would support Israel militarily unless possibly its threatened with total destruction.  Russia under Putin might be rash enough to prompt a major conflict between its allies/puppets and Israel but their likely to be attacking from Syria/Lebanon only.  N Korea I think has largely lost contacts with Russia and depends on China so I would expect while they might make some anti-American rants on 'principle' they wouldn't get directly involved.  Not sure what side Turkey would go as while its a de-facto ally of Russia at the moment because both it and the Assad regime hate the Kurds any Turkish leadership with any sense will deeply mistrust an expansionist and aggressive Russia.

  If there was any danger of WMD being used then I think even Putin would seek to end the conflict ASAP as once Israel gets desperate enough to use some of its nukes things get very, very dangerous and unpredictable.

One little (but very important) detail is that Iran is not an Arab country at all. And honestly, I see no way at all to get them to fight side by side with the Saudis. As always, the hatrrd of different sects of the same religion is far greater than the hatred of other religions. Furthermore, outside of America, there are very few western countries that want to go to war in the Middle East. But, even then, Israel will probably win, even if it takes nukes.

True, and although the European countries won't attack them for it, there will certainly be economic sanctions too, which hurt a lot.

True, which will force them to other sources, which could be Russia or Iran.

Yes, I wonder where we could find such countries...

Venezuela is a wildcard. I can see an uprising of sufficient magnitude eventually happening, perhaps supported by the CIA, that leads to Maduro's overthrowing and the establishing of a stable, democratic government. However, time can only tell. Indeed, nations like Nigeria may benefit from an embargo. However, one must remember these Arab nations' main source of income is from oil, and Western countries their principal buyers. So it would be an economic downturn for them, at least on the long run.