The scariest thing about Syria, from the West’s point of view, may be the gap between the hair-raising scenarios senior officials are discussing about what may happen next and their limp strategies for preventing it.

Inside the Obama administration, Syria is now likened by some to a second Somalia — only at the heart of the Middle East, and with the world’s third-largest stockpile of chemical weapons. One official recently described a near-term future in which the current, two-sided civil war breaks down into a free-for-all in which Sunni forces fight Kurds and each other as well as the Alawi remnants of Bashar al-Assad’s army; where the al-Qaeda branch known as Jabhat al-Nusra gains control over substantial parts of the country; and where the danger of chemical weapons use comes not just from the regime but from any other force that overruns a chemical weapons depot.

A senior French official in Washington last week had his own vision: After losing a battle for Damascus, Assad and his forces stage a two-phase retreat, first to the central city of Homs and its hinterland along the Lebanese border, then, as a last resort, to the Alawi heartland along Syria’s northern coast. This probably won’t happen within weeks, he added — but it’s likely a matter of months.

So how to stop this? The United States and France, along with a few Arab and European allies, are convening yet another diplomatic conference this week in Marrakesh, Morocco. They are hoping to bolster the opposition political coalition they strung together last month, known as the Syrian National Coalition. The Obama administration will probably recognize it as Syria’s legitimate government. More paper will be flung at Jabhat al-Nusra, which will be added to the State Department’s list of terrorist organizations.

No one is convinced that this will stop the nightmare scenarios from coming to pass. For one thing, the coalition has yet to establish firm links — much less command or control — over the scores of rebel fighting units across the country, though the formation over the weekend of a new rebel military council was a step in the right direction. The coalition is getting money from France and a couple of other governments, but the State Department’s lawyers have ruled that the United States cannot directly fund rebel organizations. Al-Qaeda’s units are meanwhile flush with contributions from Saudi Arabia and elsewhere.

The U.S. view of how its strategy will work depends on an extraordinary cascade of unlikely events. First, the coalition will gain control over most of the rebel forces. Then Russia or dissident Alawites will force Assad aside. Then there will be negotiations leading to agreement on a transitional government.

A slightly more likely scenario is that the West will get lucky and Assad’s regime will soon collapse in Damascus. In the resulting vacuum, the coalition will gain recognition from the outside world, and most of the rebel forces and Syria will follow the shaky path of Libya, with a weak government coexisting with a panoply of militias — some of them allied to al-Qaeda. The difference is that any spillover of terrorists and weapons will affect not Mali, but Israel, Turkey, Iraq and Jordan.

The main reason this is unlikely to happen is that for Assad and much of the Alawite elite — and for their chief sponsor, Iran — the West’s nightmare scenarios don’t look so unattractive. Better to hold out in an enclave, the minority ruling sect will conclude, than risk annihilation at the hands of vengeful Sunnis. Better to be a spoiler in an anarchic Syria, figures Shiite Iran, than to see a strategic ally flip over to the opposing Sunni bloc.

If Syria’s war takes this most likely of courses, how will the United States and its allies protect their interests? Officials seem to have no plan, other than to hope that the scenarios they are thinking about won’t happen. The most obvious step would be to see to it that the forces the West favors — the mainstream rebel fighting units — are at least as well armed and equipped as the Alawis and the jihadists. But for now the United States is ensuring the opposite, by denying military aid to secular rebels even as Islamist governments arm their favorites.

As for the chemical weapons, the West’s hope is that Assad isn’t serious about using them, even though his forces have reportedly mixed the precursors of deadly sarin gas into bombs. But what if he does? President Obama warned again last week of “consequences” — but is the United States prepared to take quick military action in the event of a sudden chemical weapons attack? If not, how would the atrocity be stopped?

File that under questions that won’t be answered by the “Friends of Syria” in Marrakesh.