After more than four years of war, former U.S. Ambassador to Syria Robert Ford sees a fragmented country emerging, with six or more fluid and shifting zones of control:

**An Alawi/Hezbollah-controlled area along the Lebanese border and the Mediterranean coast, backed by Iran and Russia;

**The northwest, controlled by the armed faction known as the Army of Conquest (Jaysh al-Fateh), which includes but is not controlled by Jabhat al-Nusra and is backed by Turkey and Qatar;

**The eastern two thirds of Syria, controlled by the Islamic State (ISIS);

**Most of southern Syria, controlled by the Free Syrian Army’s Southern Front and associated factions, which are backed by Jordan and Saudi Arabia; pockets of Nusra-controlled areas will be present as well;

**In Damascus, all of the above factions as well as the Islamic Army will hold different neighborhoods;

**The north center and northeast will be controlled by Kurdish fighters, who have benefitted from American close-air support.

Bashar al-Assad is unlikely to "fall" to one or another of his opponents, but he and his regime have already lost control of most of the country and will likely lose more.

In this scenario, how can the United States defend its interests in 1) avoiding a safe haven for extremists who might target U.S. interests and 2) preventing destabilization of neighboring countries?

The Russians, Iranians, and Alawis can be relied upon to repress any Sunni extremist activity in the west of the country. The United States will need to pressure Turkey and Qatar, which have been ambivalent about extremist groups that appear to target the Syrian regime, to control extremists in the northwest. Damascus will be a mess, but it is unlikely to export terror or many more refugees. Most Damascenes who want and have the means to leave have already done so.

The main foci of American attention should be the north along the Turkish border under mainly Kurdish control, and the south along the Jordanian border and the Israeli-occupied Golan Heights. In these two areas, forces friendly to the U.S.-led anti-ISIS coalition are dominant and can be supplied from neighboring areas.

The needs in the north and south are those of most war-torn territories: security, justice, governance, and jobs and social services, especially education and health.

Little will be achieved unless these "liberated" areas of the north and south are relatively secure. They need protection from attack. On the ground, they should take care of themselves, with weapons supplied from Turkey and Jordan. Provided anti-aircraft weapons, they would also be able to protect themselves from the Syrian Air Force, which continues to plague opposition-controlled areas with barrel bombs. Alternatively, the U.S.-led anti-ISIS coalition could tell the Syrian Air Force that an attack on these two areas will precipitate a punishing coalition response.

The regime's police and courts have collapsed both in the Kurdish north, where Kurdish forces temporary replacements under a regional administration, and in the south, where local administrative councils are struggling to fill the gap in governance and justice. It is vital that they be helped to succeed with salaries, training, and organization. People cannot live long without law and order as well as dispute resolution mechanisms. The extremists' ability to provide these services has generated support despite the brutality of their means. Moderates need to be given the means needed to compete.

The economy and social services in both the Kurdish-controlled north and the opposition-controlled south will remain rudimentary until a semblance of security returns. Agriculture and war-related smuggling are likely the two most important economic activities at present. The war has seriously damaged health and education facilities throughout the country. Many teachers, doctors, and nurses have fled. Getting them back to the northern and southern protected areas should be a priority.

Liberated areas in the north and south, if properly protected, might attract at least some Syrian refugees back from neighboring countries. With donor fatigue growing, Turkey, Lebanon, and Jordan would all like to be relieved of refugee burdens, including the very real possibility that extremists are making headway among youth in refugee camps and neighborhoods. Turkey, however, will be suspicious of Kurdish ambitions and will need reassurance that an independent Kurdish state is not in the cards.

With some semblance of fragmented order reestablished under Kurdish control in the north, Arab opposition control in the south, and regime control in the west, the Islamic State, headquartered in Raqqa, would still be a problem for the United States. The Syrian Kurds are unlikely to move much farther south than they already have, preferring to consolidate control over Kurdish-majority areas along the Turkish border. Arab opposition forces that have been fighting alongside them could harass the Islamic State closer to Raqqa, but without American air support they are unlikely to see real success. Meanwhile, the Islamic State will continue to try to expand its rule of Sunni areas in northern and western Iraq, challenging the Iraqi Kurdish peshmerga and moving closer to Baghdad while looking for opportunities to provoke Shi‘i abuses against Sunnis.

A new equilibrium of this sort would not be self-sustaining or entirely coherent. It would require continued U.S. willingness to attack the Islamic State from the air, especially if ISIS seeks to restore oil production or make headway against the Kurds. Protected areas north and south will also require civilian support, especially salaries and training, in order to achieve even modest success in governing and administering justice. In the south, the opposition will continue to fight the Assad regime, defying American priorities, whereas in the north the Kurds will be trying to ensure their future autonomy, if not independence.

The fragmentation of Syria could of course end in partition, that is, formal de jure separation of its component parts. Keeping them together and restoring even weak central authority will not be easy, but there are still good reasons to avoid breaking up the Syrian state, not the least that both pro- and anti-regime Syrians do not want it to happen. Nor do their respective supporters in Iran and the Gulf.

Read moreover, the lines between the six components sketched above are not clear. Any formal partition would risk even more ethnic and sectarian cleansing than has already occurred and rouse armed groups to fight over control of the country's limited oil, gas, and water resources. It is still best to prevent Humpty Dumpty from falling off the wall. Remember what all the king's horses and all the king's men couldn't do.