While under the last Constitution Syria was an “Arab Republic” it was NOT an “Islamic Republic” and Islam was not a “state religion either”. In fact the president was not required to be a Muslim. The features constantly irritated the Saudis and other Islamists. What they, and the Muslim Brotherhood wanted WAS an “Islamic Republic”. It was no wonder they supported regime change against Assad, who as an Alawite Muslim was to many Sunnis an apostate.
Saudi’s were motivated by oil and land and subjects.
They have a lot of money. They don’t have a lot of productive land. Syria has that. (along with a lot of desert too.)
And don’t discount the pipeline project either.
Erdogan’s plan was to subject the EU by invasion and by oil delivered to the EU.
Poison pill.
It is still a Republic in name only. In reality it looks more like a hereditary monarchy.