President Barack Obama’s new campaign against the Islamic State of Iraq and al-Sham (ISIS) has for the moment overshadowed the question of the United States’ overall strategy toward the Syrian civil war. But perpetual conflict in Syria will make ISIS all the more difficult to contain, and the chaotic Middle East all the harder to stabilize. It remains imperative for the United States to get its Syria policy right. And that policy needs to be rebuilt from the ground up.

For three years, the principal US goal has been to cajole Russia into supporting a political transition in Syria based on the power-sharing plan between members of the Bashar al-Assad regime and the opposition that was set forth in the June 2012 Geneva Communiqué. But at the United Nations Security Council and at the successive Geneva peace conferences, the Russian government has merely backed the Assad regime, a strategy that has effectively prolonged the shooting war and helped promote the rise of ISIS. The group’s recent advances have prompted the United States to launch airstrikes against the group in both Iraq and Syria, and to form a broad anti-ISIS coalition including European allies, and regional Sunni-ruled states such as Turkey, Jordan, and Saudi Arabia, with varying degrees of commitment. But ISIS has proved difficult to dislodge in Iraq and its strongholds in north-central and northeastern Syria may be hard to dismantle for some time. We cannot wait for the defeat of ISIS to develop a larger plan for reducing violence and ending the Syrian conflict.

Estimates of ISIS’s manpower range from 15,000 to 50,000 fighters. The most informed assessments suggest a core of 10,000 to 15,000 local fighters split between Iraq and Syria, plus over 10,000 foreign fighters, for a total fighting strength of between 20,000 and 30,000, recruitment having spiked after dramatic advances by ISIS in Iraq this summer. Since the group has gained control of much of northern and eastern Syria, a post-Assad Syrian state dominated by the largely Sunni Muslim opposition would be vulnerable to the influence of ISIS and other jihadist organizations and could eventually encourage the spread of terrorism in the region and perhaps globally.

President Obama was surely correct in declaring that Assad will “never regain the legitimacy” he has lost. In the long run, only continued pressure on Assad and support for non-extremist rebels will produce the kind of political balance required to produce an acceptable national power-sharing deal—one that must include Sunnis, Alawites, and Christians. But only slow, painstaking diplomacy could lead to such an outcome, and the conditions for such diplomacy do not now exist. Moreover, it would be naive for the United States and its partners to hope that a revived Geneva process might produce it.

The most realistic short-term policy goal in Syria is to find ways to limit the areas of the country in direct conflict, with the aim of both containing extremist violence and significantly reducing the number of non-combatant deaths. This goal is not as far-fetched as it sounds, and there is already a basis for pursuing it: through a series of local cease-fires that could, if properly implemented and enforced, provide a path toward stability in several regions of the country, even as conflict continues elsewhere. In particular, clusters of cease-fires around Hama, Homs, and Damascus, and possibly Aleppo, could help end the conflict in a larger region along Syria’s principal north-south axis, bringing a degree of normality to daily life in a vital sector of the country.

The regime has recently made efforts to negotiate truces with opposition forces in a number of these areas, and has had some success. In a probing report released in June, the London-based consulting company Integrity Research and Consultancy identified twenty-six truces reached in 2013 and 2014 and noted dozens more in various stages of development in the Damascus suburbs, parts of Homs, and elsewhere. These deals have involved Islamist as well as relatively secular opposition groups, though not ISIS.

Integrity further observed that the cease-fire reached in Homs—a city that was once described as “the capital of the revolution” against Assad and that was under siege for many months—was exceptionally effective. Initially reached in early May to allow besieged and starving opposition fighters to evacuate the Old City, this truce was backed by the UN and gained support even from hard-line fighters from Jabhat al-Nusra, the Islamist group that al-Qaeda has named its representative in Syria. In the months since, it has evolved into a comprehensive cease-fire encompassing the northern al-Waer neighborhood, which includes many opposition supporters and houses thousands of displaced people from other parts of Syria. Although compliance with the agreement has been predictably erratic, rebel and regime forces have arrived at a workable modus vivendi. In late July, Ian Black, a journalist for The Guardian, described residual conflict in al-Waer as “mostly static and curiously intimate,” and noted that residents, including state employees, commute uneventfully to and from work each day through government and rebel checkpoints just a couple of hundred yards apart.

Together with other local truces, the cease-fire in Homs provides a glimpse of what a more ambitious plan for reducing violence in Syria might look like. Under this classic “inkblot” strategy, such cease-fires could turn into more lasting arrangements for local governance—arrangements that could gradually coalesce into larger and larger areas of stability. The rebuilding of civil society in these areas would in turn be reinforced by international economic assistance and monitoring aimed at giving populations in embattled provinces like Aleppo and Homs more autonomy to choose their governors and run local institutions. But to avoid the mistakes that occurred in Iraq, wholesale dismantling of extant Syrian institutions would have to be avoided. For example, the Alawite-dominated ruling class in Damascus would retain a high degree of influence in the (by definition centralized) national army, while local populations could be given greater control over police and other security forces. Progress along these lines could reduce enmities among the different sides, and encourage exiled Syrians to return to stabilized regions of the country—a step that would help reverse the catastrophic human displacement of the war and persuade oppositionists that local truces can bring tangible results.

Recent developments in the Syrian conflict make this approach more attractive. Quite apart from the new threat posed by ISIS, military gains by rebel groups in recent weeks have sapped the Assad regime’s military momentum. Regime fatalities increased steeply to 1,100 in the month of July. Government insiders, recognizing that the longer the war is prolonged, the more the government’s institutional capacity and material resources will be eroded, have taken to calling the local truces “reconciliations.” For their part, mainstream opposition groups, alarmed by ISIS’s success in the north and northeast, may be more inclined to establish truces with the regime in areas they control in order to bring in aid, help consolidate some degree of local autonomy, and concentrate on thwarting ISIS infiltration and domination. This is particularly a concern north of Aleppo, where ISIS is threatening to take control of border crossings with Turkey that are critical to providing mainstream rebel groups with supplies, training, and humanitarian aid. In turn, local deals that ease aggression by the regime would also reduce the temptation for rebels in these areas to forge tactical arrangements—including truces—with ISIS against Damascus. (There have been reports that the Syrian Revolutionary Front (SRF), a non-extremist rebel group, is seeking a truce with ISIS south of Damascus because its forces are badly depleted from fighting the regime, though the group has denied this.)

Late last spring, a local rebel fighter in opposition-held east Aleppo told journalists that his group disavowed ISIS, which had committed many atrocities near the city, and that he viewed the cease-fire in Homs as a better way forward. “We are not surrendering, because we will prevent Assad from staying in power,” he said, “but through other means. Nobody can prevail with weapons.” These considerations suggest that cease-fires may be feasible even in areas that have not reached a state of total devastation. Notwithstanding rebel claims that the Syrian government has helped create ISIS to divide the opposition, the mainstream opposition and the regime’s common enemy is ISIS.

Such an approach would face major challenges. There are serious weaknesses, for example, in the existing truces. According to the Integrity report, these deals have been vague and hard to enforce, and have had a disappointingly small impact on safety and living conditions. The report further notes that the agreements have generally lacked three key components of sustainability: strong disincentives to pursue further attacks; confidence-building measures such as shared management of local security and fair distribution of humanitarian aid ; and restraints on escalation of violence in case of breach. Many if not most of the existing deals, moreover, have been struck in areas that had been subject to intense violence and medieval siege tactics and reached a point where the local or regional opposition group in question faced military collapse, or the civilian population in the area was on the verge of calamity. The Assad regime’s aim in making these local deals has largely been to exploit the rebels’ dire straits and free up scarce military resources for fighting the groups that pose more severe threats.

In and around Aleppo itself, Syria’s largest city and a major logistical hub in the northwestern part of the country, a cease-fire-based plan might face additional obstacles. Aleppo has been fiercely contested for the past two years, with neither the regime, nor opposition forces gaining a clear advantage. Integrity’s assessment indicated only one pending local cease-fire near the city, compared with over a dozen in southwestern Syria. Moreover, Jihadist groups have increased their control of the area around the city and ISIS has captured a number of villages in Aleppo province this summer. At the same time, the Assad regime has roughly 6,000 regular and shabiha paramilitary forces, advised and assisted by highly capable Iranian Quds Force and Hezbollah personnel, guarding Aleppo’s eastern suburbs. But there have been indications in recent months that discussions involving Iranian and Turkish interlocutors have entertained a possible cease-fire in Aleppo that would loosely follow the Homs model. Many reports also suggest that the city’s population, as well as many rebel fighters there, are exhausted by the fighting and long for stability.

Even if such discussions bear fruit, however, regime and opposition groups seem unlikely to achieve more deliberate long-term cease-fires on their own. There appears to be no regime figure or grouping with sufficient bureaucratic clout, personal integrity, and political will to pitch a deal to the opposition and implement more sustainable plans to end violence. Stretched for resources, the regime has little other than military forbearance to offer in exchange for opposition cooperation, with no adequate civil institutions or material wherewithal for substantial development assistance. The non-extremist opposition too is increasingly strained in its ability to organize civil society, and even more lacking in cohesive, authoritative leadership. In addition, the almost complete absence of mutual trust makes an unmediated strategic breakthrough highly improbable.

It is essential, then, for an international body with sufficient authority and credibility on both sides to bring the parties together in the areas where such deals are possible. The only such body in the current crisis is the United Nations, which has played an integral part in sustaining the Homs cease-fire and has already called for more such agreements. The immediate goal should be to get the regime to agree to allow personnel from the UN and from non-governmental aid organizations into areas subject to truces. Once recognized by both sides, such personnel could protect local populations while working to advance reconstruction and stabilization with local councils.

To have a more lasting effect on the Syrian conflict, however, a cease-fire plus development approach would also need endorsement from the United States and the regional powers supporting the Syrian opposition. The Assad regime would probably demand provisional assurance from foreign governments like Saudi Arabia, Qatar, and Turkey, that they would stop backing efforts to dislodge it by force. These three countries have most energetically opposed the regime and supported the opposition. They see US restraint as having emboldened the Assad regime and believe that US policies—along with support for Damascus from Iran, Hezbollah, and Russia—have permitted the regime to resist outside pressure. Moreover, while these states have given some support to the US-led effort against ISIS, some of their ruling elites may still consider toppling Assad the overriding priority.

Most Arab states are increasingly concerned about militant Islamism, and the United States and its more enthusiastic partners should be able to obtain at least the tacit agreement of such states with the cease-fire initiative through back-channel contacts. To ensure that kind of support, the plan would need to give special recognition to Sunni areas of Syria such as the Homs-Hama corridor. This should include pledges of major economic assistance to those areas, a guarantee of some form of autonomous rule, and a long-term commitment to a national political transition that gives the Sunni majority a major voice in government. Indeed, given Sunnis’ majority status in Syria, Syrian opposition groups and their foreign backers would accept nothing less—and, without such guarantees, might well fight for decades longer to oppose what they view as an illegitimate, Shia-allied regime.

Washington and its allies could also threaten limited and genuinely multilateral military action against Damascus—as they did in Libya under NATO auspices—should the Assad regime renege on local cease-fire agreements. Making such threats, however, might commit the United States to intervening in Syria’s civil war in earnest—the very outcome the plan proposed here seeks to avoid. Thus, it would be more prudent to leave any such threats against the regime implicit. Although air strikes against ISIS positions, already under way in Iraq and Syria, may raise unwanted perceptions that the anti-ISIS coalition is effectively functioning as the Assad regime’s air force, they also demonstrate the United States’ more general willingness to use force to bring order to Syria without expressly committing it to directly attacking the regime. (To blunt inferences of US support for Assad, the US will need to limit the extent to which it pursues strikes on ISIS in the western part of Syria, near areas substantially controlled by the regime. In these areas, US-supported training for non-extremist rebel forces—crucial to their ability to hold territory over the longer term against the regime and ISIS anywhere—will ultimately be important for degrading ISIS as well.)

To have the best chance of long-term success, the United States should also start preparing the ground for exploratory talks with Iran on Syria. Neither Washington nor Tehran wants to complicate pending negotiations on the nuclear issue with other matters, but this means only that public bilateral discussions on Syria need to be avoided. Secret bilateral talks between Washington and Tehran, perhaps through intelligence officials, warrant serious consideration. In Iraq, Tehran has had an important part in pressuring Iraqi Prime Minister Nouri al-Maliki to resign and welcoming incoming Prime Minister Haidar al-Abadi in parallel with the Obama administration, and it has discreetly indicated that it would consider bilateral dialogue with the United States on repelling ISIS in Iraq.

US-Iran cooperation in Syria would be more difficult, but is not out of the question. Tehran regards an Iran-friendly Syria as an indispensable bulwark against Sunni states and is providing the Assad regime with weapons, cash, and direct military assistance. But the involvement of Iran’s Quds Force and Hezbollah in the fighting has come at great cost to Iran and its proxy Hezbollah, and Syria’s instability has also damaged Iranian interests in Iraq and Lebanon. The Iranian leadership has indicated that it thinks Assad himself has dealt ineptly with the insurgency, and that if Iran could extricate itself from Syria while retaining most of its influence there and containing the growth of ISIS, it would be in its interest to do so.

Tehran has proposed several plans for resolving the conflict—though apparently none involving Assad’s departure—and might accept a scheme under which Alawites could retain substantial power in a newly decentralized Syrian state. By enfranchising mainstream Sunnis and holding Sunni radicalism and extremism in check, the decentralization plan outlined here would also answer Russian concerns about terrorism and possibly induce Moscow to participate more constructively in the international response to the Syrian crisis. Finally, if the Syrian regime showed willingness to cooperate on development and decentralization, the United States and its partners might consider incremental sanctions relief for Damascus to induce further cooperation.

The Syrian state has already effectively collapsed. The country has split into pieces, is stuck in a civil war now in its fourth year, and is experiencing one of the largest humanitarian crises since World War II, with almost 200,000 dead, over 3 million refugees, and 6.5 million internally displaced people. Continued intense fighting will only amplify the havoc wreaked by ISIS and other jihadist groups. It is repugnant that Assad is still in power, but his immediate departure is not realistic. A narrow focus by the US and its allies on ISIS—a campaign that may benefit the Assad regime and,perhaps tangentially, other violent Islamist groups like Jabhat al-Nusra as much as it helps the non-extremist opposition—will not bring Syria the stability required to contain the regional threat of Sunni jihadism.

Regardless of who is in power, Syria is ungovernable as it is constructed today. Its emphatically top-down, centralized system may have worked when its population was a mere eight million people but cannot cope with one that has increased threefold to 25 million over the past generation. Regime insiders understand this, and have already hinted at the need for greater “self-determination” or “decentralization.” On account of the growing threat from ISIS, the US now has greater leverage to persuade the countries that have most strongly backed the Syrian opposition to mute their insistence on bringing down the regime and instead focus on reducing violence and increasing stability. At the same time, the Obama administration must keep in mind that neither regional powers nor the Syrian opposition itself will allow near-term cease-fires, development efforts, and de facto decentralization to turn into a “deal” whereby Assad’s autocratic regime can stay in power indefinitely. Nor should they. Syria’s genuine transition will have to wait, but it will also have to come.

Steven Simon was the National Security Council’s senior director for the Middle East and North Africa from May 2011 to January 2013. Jonathan Stevenson was the NSC’s director for political-military affairs for the Middle East and North Africa from November 2011 to May 2013.