CAIRO — Former Yemeni strongman Ali Abdullah Saleh’s death at the hands of his own allies, the Shiite rebels known as Houthis, has put the impoverished nation’s 3-year civil war at a crossroads, and there are several widely differing directions it could now go.

It could mark the beginning of the end for the Iranian-backed Houthis — as their opponents are hoping, trying to forge a force out of Saleh’s angry supporters to assault the rebel-held capital, Sanaa.

Equally, it could show the strength of the Houthis: They easily eliminated the once-mighty Saleh, who had previously ruled Yemen as president for more than 30 years. They also broke the military units loyal to him, leaving his camp in disarray.

That’s a sign of how complicated the conflict is. The fighting has been deadlocked for more than a year. Despite a punishing air campaign, the Saudi-led coalition backing President Abed Rabbo Mansour Hadi has been unable to gain further ground against the Houthis, who control the north and western part of Yemen, where most of the population lives.

The war has caused profound misery among Yemen’s 28 million people. More than 10,000 civilians have been killed in fighting and airstrikes; food-supply and medical infrastructure has collapsed, causing a humanitarian emergency of hunger and cholera.

Here is a look at Yemen’s power players, what happened and what could happen next.

THE HOUTHIS

Originally a religious movement aimed at reviving Yemen’s Zaidi branch of Shiism, Ansar-Allah, the group’s official name, fought a series of wars against Saleh after his army killed its leader, Hussein Badr Eddin al-Houthi, in 2004. But after Saleh’s fall, he backed the Houthis and they overran the capital in 2014.

Saudi Arabia and its allies say the group is a proxy for Iran, accusing it of providing weapons and missiles, a claim Tehran denies. The Houthi forces are battle-hardened and have a constant supply of new recruits from their heartland in the north. They have emerged as warlords with a powerful, repressive hold, detaining thousands, imposing heavy taxes and engaging in black market business.

SALEH’S CAMP

During his three decades as president, Saleh built an extensive network of allies among tribes, the military and his political party. His sons and nephews commanded the main military branches. Much of that remained in place after he was forced to resign in 2012 and was replaced by Hadi.

Hoping to ride the Houthis back to power, Saleh threw that network behind the rebels.

But they never trusted each other. The Houthis quietly sucked away Saleh’s strength, winning over his tribal allies, seizing his armories and wooing his military commanders. Analysts believe the large majority of Saleh’s forces quit and went home or dissolved into Houthi ranks. Only a few remained in his camp, particularly the Special Guards unit, part of the Republican Guards once headed by his son Ahmed.

When Saleh turned against the Houthis, he “made many miscalculations; he thought the street will rise up; the forces will fight with him; the tribes will get together,” one of his former associates, Gamal Ammar, told The Associated Press.

THE SAUDI-LED COALITION

The coalition launched its campaign of heavy airstrikes along with an air, sea and land blockade in March 2015 after Hadi’s government was driven out of the capital and nearly out of the country by the Houthi onslaught. The coalition succeeded in pushing the rebels out of the southern and eastern provinces — then deadlocked.

On the ground, the coalition fights with a mix of Yemeni army units loyal to Hadi, southern secessionist militias, the armed branch of the Muslim Brotherhood and ultraconservative Islamist fighters. Most of his forces are centered in Marib, east of Sanaa. Hadi has been in self-imposed exile in Riyadh for most of the war. In the south, the UAE has become the dominant power, setting up its own militias and undermining Hadi’s authority.

WHAT HAPPENED IN PAST DAYS?

The Saleh-Houthis alliance deteriorated for months; he resented their domination of power, they suspected he was secretly talking to the coalition. Last week, outright battles over Sanaa erupted between their forces. They fought for six days with artillery, heavy machine guns and tanks, trapping Sanaa residents.

During the fighting, Saleh and Hadi’s government each said they willing to put aside their past enmity and join forces. But on Monday, the Houthis gunned down Saleh, and by nightfall they retook most of the capital from his forces.

WHAT COULD HAPPEN NOW?

The Houthis have sole domination over northern Yemen without their untrustworthy partner.

But they are alone, without the political support Saleh brought them, “stripped of any cover and shown purely as a religious sectarian movement ruling with force and repression,” said Majid al-Madhaji, from the Sanaa Center for Strategic Studies.

The coalition and Hadi will try to unify the remnants of Saleh’s supporters and forces and rally them against the Houthis. The forces need a leader, and the most plausible one is Saleh’s son Ahmed, the former Republican Guard commander, reportedly under house arrest in the United Arab Emirates.

With Saleh’s forces, Hadi and the coalition could launch a push on Sanaa from the mountain region of Nihm just to the east, backed by escalated airstrikes. They would need the backing of the seven big tribes in the areas surrounding the capital, known as the Collar Tribes, which have stayed neutral during the war, essentially allowing Houthi control. They are seen as likely to side with whoever seems stronger.

The plan is that a ground advance on Sanaa, where the Houthis’ hold has been unquestioned since 2014, could break the stalemate.

“The road to get rid of Houthis is becoming clearer and easier,” al-Madhaji said, calling the end of the Saleh-Houthi alliance “a free gift” for the coalition.

“The question is if it’s able to exploit it.”

HOWEVER….

The answer to that question is not a sure thing. Even if Saleh’s forces can rally, there’s no guarantee they can tip the balance against the Houthis. The Collar Tribes won’t join unless they believe the Houthis will be beaten.

The anti-Houthi forces are riven by conflicting agendas that have undermined their ability to prosecute the war, like the interminable battle for the city of Taiz.

The UAE, one of the coalition’s main players, hates the Muslim Brotherhood — a main component in Hadi’s forces — and does not want to see it advance. The Brotherhood and their patron — Hadi’s top commander and vice president Ali Mohsen al-Ahmar — hated Saleh and may resist working with his supporters.

The Houthis remain a formidable military force. They have already withstood more than two years of relentless coalition bombardment.

If the war turns decisively against the Houthis, Iran could intervene more substantially to rescue them.

“It would be a risky move, but I see it as a real possibility,” said Will Picard, the executive director of the Yemen Peace Project, a Washington-based think tank.