How about a fractured and broken up Syria with several armed fiefdoms in control of terrorists?

On Israel's border.

New York Times:

The black flag of jihad flies over much of northern Syria. In the center of the country, pro-government militias and Hezbollah fighters battle those who threaten their communities. In the northeast, the Kurds have effectively carved out an autonomous zone.

After more than two years of conflict, Syria is breaking up. A constellation of armed groups battling to advance their own agendas are effectively creating the outlines of separate armed fiefs. As the war expands in scope and brutality, its biggest casualty appears to be the integrity of the Syrian state.

[...]

But as evidence of massacres and chemical weapons mounts, experts and Syrians themselves say the American focus on change at the top ignores the deep fractures the war has caused in Syrian society. Increasingly, it appears Syria is so badly shattered that no single authority is likely to be able to pull it back together any time soon.

Instead, three Syrias are emerging: one loyal to the government, to Iran and to Hezbollah; one dominated by Kurds with links to Kurdish separatists in Turkey and Iraq; and one with a Sunni majority that is heavily influenced by Islamists and jihadis.

"It is not that Syria is melting down - it has melted down," said Andrew J. Tabler, a senior fellow at the Washington Institute for Near East Policy and author of "In the Lion's Den: An Eyewitness Account of Washington's Battle with Syria."

"So much has changed between the different parties that I can't imagine it all going back into one piece," Mr. Tabler said.

Fueling the country's breakup are the growing brutality of fighters on all sides and the increasingly sectarian nature of the violence.

This is a direct consequence of an American and western policy failure to strengthen the non-jihadist opposition either politically or militarily. With no uniting force to rally around, the rebels joined independent commands - the most effective units being jihadists who are seeking to turn Syria into a Muslim Brotherhood or Salifist state. The al-Qaeda units aren't very interested in a united Syria either. They will seek to carve out their own safe haven in order to be able to operate freely in the region - and against our interests.

It's hard to see a turn of events that would be more threatening to Israel's basic security.