Syria's political fate comes down to a man, his extended family and his political entourage. When President Bashar Assad decided in March 2011 on a violently brutal response to peaceful protest, he separated himself from the interests of his citizenry. When he embarked on a survival strategy featuring mass homicide, he facilitated the rise of the Islamic State group as a political foil and created a humanitarian abomination that made Syria's problems the problems of all its neighbors and western Europe. Russian and Iranian military intervention saved him. But it will take their continued support and the application of state-destroying, Dark Ages brutality to sustain him.

For years, Assad has inflicted collective punishment on civilians while pursuing a mutually profitable live-and-let-live relationship with ISIS. During that time, he has neither hinted at personal error nor uttered the word "reconciliation." He has denied the existence of barrel bombs, chemical weapons and state terror. With some 400,000 deaths and more than half the population displaced, he takes no responsibility for anything having gone wrong.

This is not a critique of leadership style. Assad, his family and his political entourage see Syria and Syrians as personal property. Anyone questioning their rule is labeled a "terrorist." This attitude of entitlement coupled with eagerness to kill for compliance has dire implications for how a country already in ruins will be ruled if he prevails.

Assad has made it clear he aims to reestablish his sway over the entire country. He has every reason to think Russia and Iran will help him finish the job, whether the task includes ousting ISIS or simply concentrating on western Syria. He believes Russian President Vladimir Putin needs him to provide televised military bread and circuses to Russian masses yearning for great power status. He knows Iranian Supreme Leader Ayatollah Ali Khamenei needs him to keep Syria at the disposal of Hezbollah in Lebanon. He prays a new American president will enlist him in the battle against Islamist extremism.

Yet, Assad-style "stability" for Syria will have profoundly unattractive and destabilizing features. The economy — already largely in the hands of criminals (including in Assad-ruled areas) — will continue to deteriorate. Levels of investment and aid needed for reconstruction will not materialize if people known for industrial-strength corruption remain in charge. Refugees and migrants will not return. Repression — minus the barrel bombs and chemical attacks, perhaps — will be applied with vigor and inventiveness. Syria’s ruination as a state will be completed by those who began the job in 2011. Syria could, over time, all but empty itself.

The way out of this failed cul-de-sac of a state was defined in Geneva in June 2012 when the permanent five members of the United Nations Security Council agreed on a procedure to bring about political transition. Iran was not part of that arrangement. Russia backed away from its terms to save Assad instead. Although the "Final Communique of the Action Group on Syria" survives, clearly military facts on the ground will dictate the manner in which it is implemented, if at all.

For Moscow, having Assad serve out his term as president until 2021 under a revised constitution according him largely ceremonial duties, while a negotiated "transitional governing body" built on the basis of mutual consent (consistent with the Geneva agreement) exercises actual executive power, could be an attractive scenario. Putin could claim that he defeated US President Barack Obama’s alleged attempt at regime change. A government reflecting national unity and technical expertise could attract reconstruction assistance while sustaining a warm relationship with Moscow.

For Tehran, Assad exercising ceremonial powers could be problematical. Tehran knows that Syrians take a dim view of subordinating their country not only to Iran, but to Hezbollah. Only Assad — Bashar, the clan and the entourage — is fully reliable. Moreover, Tehran needs time to build in Syria a power structure analogous to Hezbollah in Lebanon — something that would permit it to dominate Syria irrespective of what happens to the regime.

As for Assad himself, why would he yield or share power? Iran can be counted on: It needs him to help sustain Hezbollah’s imprisonment of Lebanon and its rocket and missile threat to Israel. Russia? Putin needs him and may be powerless to sideline him in any event. In Assad’s warped calculation, the West needs him to fight his partner in crime — ISIS — and to sit atop a restive population. He may even believe he can bribe Europeans with the threat of further heavy migration. Given the evolving state of European politics, he may be right.

Marginalizing a regime whose private interests have brought Syria to ruin is the inescapable prerequisite for political accommodation in Syria. Putin may well see the objective truth of this proposition. Iran is the fundamental external obstacle. It sees Assad as essential to the health and well-being of its own signature contribution to the menagerie of Islamist extremism: Hezbollah.

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.