There have been persistent rumors that Jabhat al-Nusra, among the most effective militias fighting Syrian president Bashar al-Assad’s regime, is linked to Al Qaeda. That connection has now been confirmed. The head of al-Nusra’s Syrian branch, Abu Mohammed al-Jawlani, has declared his organization’s “allegiance” to Ayman al-Zawahiri, Al Qaeda’s leader.

Al Nusra is not the only radical Islamist group seeking to topple Assad. Less well known, but perhaps more potent, is the Kataib Ahrar al-Sham, which at the end of last year increased its influence by creating a coalition containing several kindred groups.

This doesn’t mean that the entire armed opposition in Syria consists of radical Islamists, let alone followers of Osama bin Laden’s ideological line. Assad’s foes are a varied, indeed fragmented, lot. The divisions among them have persisted despite, and sometimes because of, the efforts of their Western, Turkish and Arab supporters to create unity. One of the reasons this horrific war drags on without an end in sight is that Assad is not facing a cohesive adversary. Yes, the Syrian opposition is outgunned, but military weakness is by no means its only problem.

Although the armed resistance has persisted despite the shortage of basic supplies, immense hardships and heavy losses, the coordination among the various groups that constitute it remains patchy. The loyalty of fighters to individual commanders or to localities has hampered coordination among the many militias as well as agreement on the basics of a post-Assad polity. The countries supporting the anti-Assad forces helped forge a National Council of Syrian Revolutionary and Opposition Forces in November 2012, and it adopted a set of common principles. But the reality is that the divisions within it remain and run deep.

The Syrian opposition’s external supporters are also not likeminded. The United States has been providing the anti-Assad forces with nonmilitary supplies and training them from Jordan. Given Assad’s resilience, the Obama administration is now said to be considering an expansion of the scope of its aid. But there’s no sign that the president is willing to provide substantial amounts of military equipment to level the Syrian killing field, let alone establish a no-fly zone or send troops or advisers into the battle zones.

Britain and France are pushing to end, rather than extend, the European Union’s arms embargo when it comes up for renewal in May, but other EU members, notably Germany, don’t share their view. Al-Nusra’s public declaration of fealty to Al Qaeda will deepen the EU’s divisions on Syria and also make Obama even leerier about arming anti-Assad fighters.

Saudi Arabia, Qatar and the other Gulf monarchies may be pleased to see a militant Sunni Muslim (and anti-Iranian) leadership emerge in Damascus. But there’s no reason the West should be; and this is certainly not a dénouement Israel desires.

Yet unless the Syrian resistance acquires the wherewithal to fight more effectively—by obtaining such items as surface-to-air and antitank missiles—it cannot prevail in what remains a seesaw struggle. The Assad regime’s foundation has cracked, but it has not crumbled, perennial predictions to the contrary notwithstanding. Advocates of arming the opposition claim that those receiving weapons can be vetted to ensure that only “moderates” benefit. That’s a nice idea in theory, but once the arms start flowing it’s going to be tough to track them, given the complexity of Syria’s political and military landscape and the fluidity of the alignments among the multitude of militias. Nor does the historical record warrant confidence about the suppliers’ ability to control the destination of the arms they provide to the insurgencies they embrace.

Meanwhile, more than seventy thousand Syrians have been killed, 1.3 million have fled to neighboring countries (which could be destabilized as a result—especially Lebanon), and some 4 million have become, to use the euphemism of relief organizations, “internally displaced persons.” Tragically, the countries championing the opposition’s cause have failed to help adequately in the one area in which they can make a big difference, and without risk or controversy: providing UN refugee agencies the resources required to manage the swelling tide of Syrian refugees. So far, only a tiny fraction of what’s needed has been received, and existing funds are drying up.

Arming the opposition will not change Syria’s harsh realities. Even if that move hastens Assad’s fall, a new round of bloodletting will follow. The regime’s diehard remnants will fight on in desperation. The ideological divisions within the opposition, contained by the focus on defeating the regime, will deepen and turn violent.

There’s only one way to end the carnage in Syria. The West should abandon its insistence that Assad must go before there can be negotiations on a political settlement. Whatever the original merits of this position, it has clearly shown itself to be a nonstarter. And by now, Assad has so much blood on his hands that he has no incentive to quit, and plenty of reasons to worry about where he will end up—assuming he is able to find safe refuge at all.

The idea of bargaining with the regime will, understandably, be unpalatable to the opposition, but if the blood is to stop flowing, its supporters should used their leverage and powers of persuasion to bring about a change of heart. Once the guns fall silent, brokered negotiations should begin aimed at creating a transitional government containing representatives from the regime and the opposition. Once that is achieved, UN peacekeeping forces should be deployed so that agreement can be reached about the terms for holding internationally supervised elections. The time to marginalize Assad and other top officials is when discussions on an interim authority get serious; and some unsavory deals will have to be done to achieve that result.

It’s not just the opposition that has tough choices to make; so do Assad and Company. There is no chance that they will vanquish the armed resistance. And the more people they kill, the harder it will be for them to work out arrangements pertaining to places of exile, amnesty, the duration and nature of punishments, and so on.

The two countries with the strongest ties to Assad are Russia and Iran. Both are savvy enough to see that, however this bloodbath ends, one outcome can be ruled out: the survival of the House of Assad. If one part of the solution to the Syrian war involves the opposition’s backers urging it to accept a ceasefire followed by negotiations, the other involves Iran and Russia leaning on Assad to accept this plan. It’s the best deal Assad’s going to get. Whatever he gets down the line will be much worse.

As it happens, Moscow is already amenable to a solution along these lines. The Russians also have a cooperative relationship with Iran and are thus best suited to bringing Tehran, Assad’s other most important backer, into the process. The United States and Russia have a working relationship, no matter how volatile it is, and can work together on Syria. Neither wants to see more Syrians killed, Assad replaced by radical Islamists, or Syria’s neighbors thrown into upheaval.

Is this suggestion guaranteed to work? Is it an ideal solution? No and no. Any solution to Syria’s civil war is a long shot at best. But this much is certain: allowing the war to proceed on its present course or trying to reshape it by arming the opposition won’t lead to good outcomes—for the Syrian people or for their neighbors.

Rajan Menon is the Anne and Bernard Spitzer Professor of Political Science at the City College of New York/City University of New York, nonresident senior fellow at the Atlantic Council and the author, most recently, of The End of Alliances.