Why is Aleppo so crucial to winning Syria’s war?

Russia is bombing rebel-held areas in Syria at a furious pace. That is giving the Syrian President, Bashar Al Assad, the upper hand. At the same time, critics accuse the United States of dithering.

The war, approaching its sixth year, may be reaching a turning point in Aleppo, Syria’s largest city and once its commercial capital. Government-aligned forces are trying to encircle its eastern half, controlled by rebels since 2012. If the government succeeds, it would be the greatest blow to the opposition in years.

But the battlefield is unpredictable. If the government regains full control of Aleppo, will the war begin to wind down, or will it escalate?

What is Al Assad doing?

Supported by the Russian air strikes, Syrian government forces and Iran-backed militias are trying to besiege the rebel-held section of Aleppo to starve the rebels into submission — the same method government forces used to recapture another major city, Homs. Using starvation as a weapon is a war crime, but it has been widely used in Syria.

Government-aligned forces have also severed the main supply route to Turkey that delivered food, weapons and aid to rebel areas, leaving one remaining route.

The United Nations has warned that about 300,000 people in the rebel-held part of Aleppo could be at risk of starvation.

The Syrian government has also succeeded in turning humanitarian aid — food — into a negotiating chit. In talks to end the fighting among world powers on Thursday, allowing food deliveries was offered as a government concession.

Who controls what?

According to an analysis by the Carter Centre, of the population centres each faction controls, the government has about 40 per cent of the country, while the Kurdish groups, Daesh and other rebel groups each hold about 20 per cent.

The rebel groups that the West considers relatively moderate are strongest around Aleppo. But they are intertwined in places with the Nusra Front, which is linked to Al Qaida and which the United States and Russia both consider a terrorist group. The deal reached in Munich, for a “cessation of hostilities,” leading to a ceasefire, excludes the Nusra Front and Daesh.

The rest of Aleppo province is a patchwork of zones of control. Kurds have the area around Afrin in the northwest, Daesh holds the east, the government and its allies have advanced in the south, and other rebel groups hold the west.

Why is Aleppo so crucial?

Al Assad may never be able to stitch Syria back together. But he and his allies now believe they can add Aleppo to a core area they control that includes the capital, Damascus, and Homs. That would give the government control of the cities that were the main population, cultural and economic centers of Syria — though rebels still hold Idlib, which lies between them.

Still, it could take a long time for the government to re-establish full control of Aleppo. And even if it succeeds, it is possible the rebels and their backers will retreat and change tactics, as the rebels in Iraq did. That could mean that even a nominally government-controlled Aleppo could still suffer sporadic attacks.

What is the situation in Aleppo?

More than 300,000 people live in the rebel-held side of Aleppo, and at least twice as many in the government-held west. Government troops occupy the historic citadel, while the Old City is contested. Both sides of the city have suffered indiscriminate shelling and water and electricity cuts. The rebel-held side is being pounded by government and Russian air strikes and barrel bombs that have hit markets, schools and homes.

In the countryside, foreign Shiite fighters, trained and sometimes led by Iranian commanders, are fighting on behalf of the government alongside the Syrian army. Coming from Lebanon, Iraq, Afghanistan and Iran, those forces recently broke an rebel blockade around two isolated, pro-government towns, Zahra and Nubol.

Rebel-held rural areas in Aleppo province are boxed in between government and allied forces, Kurdish militias, Daesh and the Turkish border, which is closed to most refugees. The Kurdish militias, with some Arab allies, have advanced into territory ceded by Arab and Turkmen rebels under Russian attack.

What is the United States doing?

There is a lot of confusion over the United States’ aims in Syria. US policy has been to give rebels enough support to keep them going — not enough to help them actually win. Rebels are now asking whether the United States will let them lose outright.

The United States still insists on trying to separate the civil war from the fight against Daesh. That is a distinction the rebels largely reject, insisting that Al Assad must go. But Russia’s air power has changed the calculation so that there is little the United States can do militarily without risking a direct clash with Russia.

The United States has asserted for months that there is no military solution to the Syrian war, only a political one. On Wednesday, one senior US official conceded that there may in fact be one — “not our solution,” but that of President Vladimir Putin of Russia.