Defeating Daesh (also known as the Islamic State group, ISIS or ISIL) must be linked organically to the eventual rebirth of a post-Assad Syrian state featuring pluralism, rule of law, empowered local governance, reconciliation and reconstruction. Step one is to beat Daesh. Step two is to enable the Syrian opposition recognized by the International Syria Support Group to enter eastern Syria, link up with local councils currently underground and establish a government to administer liberated areas. Step three is for the United States and its partners to recognize that administration as the government of the Syrian Arab Republic. Step four is for that government to offer to negotiate with the entourage of Syrian President Bashar Assad, even as it builds with international assistance a Syrian National Stabilization Force capable of pacifying the country if necessary.

Routing Daesh from Raqqa, Deir al-Zour and other populated areas in eastern Syria simply must be put in the service of Syrian political transition. Russia and Assad have laid waste to the diplomatic process launched in Vienna a year ago. They, with the support of Iran, are now engaged in mass homicide centered on Aleppo. As a lethargic, American-led military campaign slowly squeezes Daesh in eastern Syria, Russian and Assad brutality produce recruits for for the ersatz "caliph" around the world.

At some point Daesh in Syria will be defeated. By whom is not yet entirely clear. But when it happens someone must administer liberated territories. It cannot be Assad: His brutal misrule created the vacuum filled by Daesh in the first place. It cannot be a Kurdish militia: The territory in question is overwhelmingly Arab. It cannot be the anti-Daesh coalition, led by the United States.

In December 2012 the United States and the Group of Friends of the Syrian People recognized the mainstream Syrian opposition — the Syrian National Coalition — as the legitimate representative of the Syrian people. In 2015 the opposition broadened itself organizationally in the form of the High Negotiations Committee, led by former Syrian Prime Minister Riyad al-Hijab. This is the body that has been prepared to negotiate, in Geneva, the successor to the Assad regime. This is the body with which all members of the International Syria Support Group — co-chaired by the United States and Russia — deal.

Sadly, the 2012 recognition statement was not accompanied by action to prepare the external Syrian opposition to govern inside Syria. Instead the governance gap was filled at local levels — in places like Raqqa and Deir al-Zour — by local councils of engaged Syrians. For the first time in its history Syria had citizens taking responsibility for self-government. Daesh drove these councils underground in the east as Assad, Russia and Iran tried to eliminate them in the west.

Decapitating Daesh will enable these councils to rise from the underground. But they are local entities capable only (though critically) of local administration. Hijab should, in the immediate wake of liberation, fly to his hometown — Deir al-Zour — and establish a technocratic government linking these councils and supporting their efforts.

The United States and its partners — upholding their commitment to the territorial integrity of Syria — should recognize this administration as the government of the Syrian Arab Republic. This will end the ongoing disgrace of recognizing a war criminal as Syria's president. The new government can take the Assad seat at the United Nations, dismissing the family retainer recently made infamous by laughing at reports of human suffering in Aleppo. And it can, as Syria's government, refer charges to the International Criminal Court, setting the stage for trying Assad and his inner circle for crimes against humanity.

Syria's new government will require external support. Humanitarian aid will be mandatory. The country's physical reconstruction can begin in the east. The oil and gas industry can be rehabilitated. The United States and its partners should establish security assistance relationships with the new government, helping it to build a professional and capable Syrian National Stabilization Force. Assad and his allies should be blocked from moving east, and the anti-Daesh coalition should be repurposed for the defense of Syria's new government. All of eastern Syria could be a no-fly zone until the new government is capable of self-defense.

Replacing Daesh with a new government will also open a new diplomatic way forward. The new government should commit itself to full cooperation with the International Syria Support Group and declare its readiness to sit with the Assad clique in Geneva and create — on the basis of mutual consent — the transitional governing body mandated by the June 2012 Geneva agreement. That body will certainly exclude criminals. But it might well include Syrian officials and military officers who have performed conscientiously and patriotically in spite of criminal leadership.

The impending defeat of Daesh in Syria should not be wasted. Russia and its client regime have shut the door to diplomatic progress. Another should be opened, whether they like it or not.

Frederic C. Hof, director at the Atlantic Council's Rafik Hariri Center for the Middle East, served as a special adviser for transition in Syria at the State Department in 2012.

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