Plainly, Syria's success – notwithstanding the caution of President Bashar al-Assad in saying that signs of success are not success itself – in resisting, against the odds, all attempts to fell the state suggest that a tipping point in the geopolitics of the region has occurred.
We have written before how the Syria outcome dwarfs that of Israel's 2006 war against Hezbollah, significant though the result of that war was, too.
Both events taken together have brought America's unipolar moment in the Middle East to an end (though not globally, since the U.S. still retains its necklace of military bases across the region). The successes have corroded badly the reputation of the Gulf States and have discredited fired-up Sunni jihadism as a "go-to" political tool for Saudi Arabia and its Western backers.
But, aside from the geopolitics, the Syria outcome has created a physical connectivity and contiguity that has not existed for some years: the border between Iraq and Iran is open; the border between Syria and Iraq is opening; and the border between Lebanon and Syria, too, is open. This constitutes a critical mass both of land, resources and population of real weight.