The name of the game is conflicting interests of all the players. No two countries have the same goals in precise terms while generally most support some vague, meaningless ideas open to broad interpretation and varying claims.
Before we try to understand what Saudi Arabia intentions are in Syrian peace negotiations’ context we have to understand from where they are coming from.
The so-called Saudi Royal Elite, described by last legitimate Caliph as a band of petty desert thieves and robbers of the camel caravans, killers of faithful Muslims on their way to Mecca for pilgrimage, was a direct product of a colonial conquest by failing British empire in late XIX century aimed to dislodge Turkish dominance and to break down the Ottoman empire.
When after disintegration of Ottoman Empire in 1918, this frail and politically insignificant group of criminals, on the payroll on British intelligence, was officially assigned by British imperial power a role of guardians of two top holly sites of Islam i.e. Mecca and Medina, there was an uproar in the Muslim world especially since those new guardians of faith were not even classified as Muslims, but a heretical sect, a cult limited in its influence only to Wahhabis, Arabian desert tribes.
Not until huge reservoirs of crude oil were discovered underneath Arabian desert in 1920-ties, this puny family of gangsters gained any importance on world political stage in a context of collapsing British imperial plans for MENA and even more when many years later an enormous wave of anti-colonial rebellions and people revolutions swept the world, destroyed old colonial order and transformed it into a cold war confrontation playground between two superpowers and their imperial hubris.
Unable to hold on to their colonies, British and other colonial powers frantically were trying to divide their colonies into some relatively weak, politically and religiously conflicted, easy to control regions and attempted to install Middle East puppet regimes in a form of fake Royalties, colonial collaborators or intelligence agents elevated to Royal class via edicts of British in ME and other European royalty elsewhere in Africa. An hence Saudi Arabia as well as other GCC fiefdoms were created, a colonial propaganda constructs, strictly controlled and financed by British and later by American imperial powers that became the only guarantors of their political and religious legitimacy as separate statelets.
In contrast to the GCC countries, this national “independence” charade did not work for long in other former British and French colonies of Iraq and Syria, Lebanon and Palestine, Egypt, etc., where Soviet trained political cadres of the populists, anti-colonial revolutionaries in late 1940-ties to 1960-ties overthrew those puppet regimes and/or former colonial powers and pushed for unifying ideology of Secular Arab Nationalism, with strong political and economic support of Soviets and that included Soviet push for establishment of socialistic Jewish state of Israel, as a misguided anti-colonial effort which conflicted with anti-colonial struggle of Palestinians and became an immediate cause of acute post-colonial conflict in the ME against original Soviet intentions.
Things got even worse when, after 1966, Israeli Yiddish leadership under pressure from US Jewish Diaspora, (perhaps) “turncoated” on the Soviets and was allowed to abandon Socialist, Zionist roots and turned into sectarian, capitalist regime it is today. In a way Israel first fell victim of “Jewish Spring-like” American subversion in order to get Israel under US imperial umbrella together with other sectarian desert thieves of GCC, a company where Jewish people did not belong.
All those developments further stabilized Saudi regime and made it indispensable in the US foreign political propaganda in a new global geopolitical context. Saudis became not only important strategic ally but a guardian of US economic power base depended on the ME oil when US oil production was programmatically declined.