Whole issue is too complicated & there are no clear cut answers.
One version is Qatar proposed shipping oil to the Mediterranean Sea thru a pipeline running thru Syria from where alternate routes running thru Turkey onwards from Syria or from the Syrian coast could take the oil & gas to the EU.
Apparently either Assad asked for a huge price or he dismissed the offer off hand. Be that as it may , Qatar got Turkey to do their dirty work.
Another version has the US & Gulf Sheikhdoms worried by the Islamists including the AQ types on the one hand & political revolution sweeping the Arab world on the other hand , decided to create instability in the Syria Iraq axes to draw these fanatics in & then entrap them there.
Iran has no choice in the matter as the ISIS following the Salafi / Wahhabi ideology see the Shi'a as bigger kuffar than other genuine kuffar as per Islamic doctrine. They had to throw in their lot with their partisans in Iraq & Syria .
Israel had not much role to play nor would it be wise by the players then to involve Israel as well , as the moment Israel's involvement became known the boot would be on the other foot.
Besides why would Israel be involved if their purpose was being served without their involvement. A decade & a half later the Assad regime is gone , Hezbollah is decapitated , Hamas is destroyed & Iran is on its knees.
All Israel has to do now is destroy the Iranian regime , wait for things to settle down & then go in for the final solution at the opportune moment i.e push all the Palestinians from Gaza & West Bank into Jordan & let the latter deal with the problem .
In all probability after the initial waves of violence & protests die down we'd see a repeat of this

except this time I don't expect the Jordanian Royal Family to emerge lucky.
View: https://youtu.be/try3LAQxSAE?si=pZJe6e5xHQaly5BZ
Come across a Paxtani shouting justice for Gaza , shove this video down his throat .