As the Islamic State (IS) has made dramatic military advances over the past few months, speculation has been growing that the regime of Bashar al-Assad might be eligible for gradual rehabilitation. As none of the countries who signed up to the U.S.-led alliance against the organization will put boots on the ground, the drive to cooperate with just about any of the local and regional actors who do is gaining momentum. And because the alliance’s preferred partners are either in disarray (like the Iraqi army), restricted to certain areas (like the Kurdish peshmerga), or barely capable of holding their ground (like Free Syrian Army), the Syrian regime’s success against IS could make the case for bringing Assad back in from the cold.

Those who advocate for such a course of action include Sir Malcolm Rifkind, the chairman of Britain’s intelligence and security committee, as well as seasoned counter-terrorism experts and academics, both the former and current chairmen of the Council on Foreign Relations, and the Republican presidential hopeful Rand Paul. Policymakers in Paris, London, and Washington have rejected the idea out of hand, citing the Syrian regime’s abysmal track record of human rights violations and war crimes. While it is certainly laudable when political leaders base foreign policy choices on ethical considerations, the question remains whether such principled positions will hold up if the current approach of limited airstrikes fails to yield results. What if, for instance, the Islamic State captures the major northern city of Aleppo or advances in the direction of Salamiyya, threatening a mass slaughter of the local Ismaili population, whom the radicals consider heretics? If cooperation with designated terrorists was acceptable to defend the Kurdish enclave of Kobani, why is it not with the Syrian regime?

Yet a closer analysis reveals that the adverse consequences of any possible cooperation with Assad far outweigh the purported benefits. It is highly doubtful whether Assad even has the military means to roll back IS. Despite vastly superior equipment, what is left of the regular Syrian military has made only excruciatingly slow progress against the badly armed and barely coordinated ragtag bands of the Free Syrian Army (FSA). Most regime-held areas are by now controlled by militias that thrive on plunder and racketeering, which will be useless in sustained combat. In recent months, small groups of rebels equipped with modern TOW anti-tank missiles repeatedly repelled regime attacks, casting serious doubt on the capacity of Assad’s army to carry out offensive action against the well-equipped and effectively led fighters of the Islamic State. In the recent past, confrontations between IS and the Syrian army have mostly ended with the latter’s ignominious defeat. The regime’s by now well established habit of abandoning its soldiers to an enemy that is known to give no quarter has further undermined its already low morale. That the Syrian army could be a “plausible ground force” against IS, as the former chairman of the Council of Foreign Affairs Leslie Gelb proposes, appears rather implausible.

That may actually be a blessing in disguise, as serious advances by this army against IS would only serve to deepen the sectarian dimension of the conflict. The most efficient units that Assad can still field are largely composed of and overwhelmingly led by Alawites, while his foreign auxiliaries—the Lebanese Hezbollah and Iranian Revolutionary Guards—are exclusively composed of Shia. If these troops were to invade the overwhelmingly Sunni areas now held by IS, it would add yet another layer to the jihadi groups’ rallying narrative of a historical battle against “heretic” traitors to the true faith. Such propaganda will be especially effective, as the track record of the regime suggests that any such invasion will be accompanied by atrocities and massive casualties among the civilian population. Furthermore, if these groups came to see the anti-IS alliance as effectively, even if unintentionally, facilitating such an onslaught, all the enemies of the jihadis—Shia and Alawites, imperialists, the West, and Arab Monarchies—would effectively blend into one foe. It is difficult to imagine a more effective recruiting tool for the Islamic State. Much more detrimental still will be the effects these perceptions would have on Sunni Muslims who do not (yet) subscribe to radical views, but who are appalled by suspected double standards of Western capitals regarding the slaughter of their co-religionists in Syria. A fatal impression is gaining ground that Western powers only swing into action when religious or ethnic minorities—Shia, Christians, Yezidis, or Kurds—are threatened.

Working with Assad would not only strengthen the appeal of jihadi groups in Syria but could jeopardize cooperation with moderate Sunnis, including parts of the Free Syrian Army. Defections to jihadi organizations will increase, and many so-called “moderate” Islamist groups may end up switching sides altogether. The effect on the regional cohesion of the alliance would be equally significant. Turkey, already a reluctant ally, has made it abundantly clear that it considers Assad, not IS, to be the main problem. If the Turkish leadership comes to the conclusion that the alliance has these priorities backwards, efforts to convince Ankara that it should stem the flow of recruits and provisions for IS across the long Turkish-Syrian border will go nowhere.

The alliance with the Gulf countries would be equally affected. Despite appearances, Gulf monarchs are not able to impose unpopular foreign policies without buy-in from elite stakeholders, family members, and religious authorities. Sectarian resentment and ideological support for radical (Sunni) Islamists run high in these societies, and private networks of wealthy and influential individuals contributed significantly to the rise of groups such as IS in the first place. At least initially, Gulf security services also contributed their own share to these efforts. If the alliance were seen to make common cause with Assad, it would be even more difficult to keep tabs on these structures, and Gulf rulers would come under increased domestic pressure to scale down their involvement or withdraw altogether.

The rulers themselves may be more worried about the destabilizing effect of the radicals on their own societies. But such concerns are eclipsed by the greater fear that Assad’s survival would support Iran’s hegemonic aspirations. The gradual rehabilitation of the Syrian regime, even if it were to rule only over a part of the country, would amount to a major strategic success for Tehran. Not only would Iran be able to solidify its influence over three Arab states (Lebanon, Syria, and Iraq)—with a combined population of 60 million (more than three times that of Saudi nationals) and a contiguous territory stretching from the Tigris to the shore of the Mediterranean—but it would also send a clear message across the region that those who have Iran behind them will be able to hold their ground. In addition to the Gulf states, Israel will weigh in with Washington to prevent any such outcome, which would amount to an implicit recognition of Iran’s regional role by the U.S. administration.

Considerations for cooperation with Assad overlook his weakness, to say nothing of the destruction it would bring to the anti-IS alliance. It could easily lead to the collapse of this coalition and would require policy choices that the U.S. in particular is not ready to take. For once, realpolitik appears to be the most solid deterrent against a deal with Assad.

This article is reprinted with permission from Sada.  It can be accessed online at: http://carnegieendowment.org/sada/2014/12/02/case-against-alliance-with-assad/hvru

Heiko Wimmen is a research associate in the Middle East and Africa division at the German Institute for International and Security Affairs (Stiftung Wissenschaft und Politik – SWP) in Berlin. He is a regular contributor to Sada.