Almost 30 years ago I was in Syria when Hafez al Assad and his brother Rifaat killed 30,000 Syrian Sunnis who had dared to defy their police state. Dissent was crushed mercilessly. Now the spring of Arab revolt has come to Syria.

The uprising led by the Muslim Brotherhood in Hamah in March 1982 was the largest protest movement in the Arab world in the wake of the Iranian revolution in 1979. The Brothers' goal was to topple Assad's Alawite minority dominated regime and create a Sunni majority Islamist state. As I watched the Assad brothers send the elite Republican Guard through Damascus that winter it was clear the Alawis were ready to fight to death to stay in power. They knew then and know now that the Sunni retribution for decades of Alawi rule and terror will be just as merciless. Hamah was pounded for days by tanks, the old city destroyed, the rebels hunted and killed. The Sunnis got the message.

So does the current unrest in the southern city of Daraa threaten to send Hafez's son and heir Bashar Assad to the graveyard of dictators? It’s much too soon to call. The son may be just as ruthless as his father and probably judges he must act decisively fast. The secret police chiefs who back him and the key generals will demand repression. But the very nature of the regime—based on the support of the 15 percent Alawi population and some Christian support—makes it a brittle state. If it starts to come undone it could unwind.

Syria has a long tradition of coups that could also be revived. If the Sunni majority smells blood, Syria could make Libya look like child’s play. Syria's allies Iran and Hezbollah must be very nervous. They need the Assads to have their access to Syria. A Sunni regime will have no love for the Shia Persians and Lebanese. Nor does Assad have other friends in the Arab world. The Saudis, Iraqis, and Jordanians will not lift a finger to help Bashar. Israel has seen little positive effects for it so far in the winter of Arab discontent.

But unrest in Syria is different especially if it disrupts the Tehran-Damascus axis and unsettles Hezbollah and Hamas. The Mossad must be watching carefully to assess Assad's staying power. For the U.S. the Assads have been consistent disappointments. They have flirted with peace with Israel especially in 2000 but never jumped. We should hope this spring will be their last.

Bruce Riedel, a former long-time CIA officer, is a senior fellow in the Saban Center at the Brookings Institution. At Obama’s request, he chaired the strategic review of policy toward Afghanistan and Pakistan in 2009. He is author of the new book Deadly Embrace: Pakistan, America and the Future of the Global Jihad and The Search for Al Qaeda: Its Leadership, Ideology and Future.