After months of a start/stop campaign, Damascus, Moscow and Tehran have vowed to recapture all of insurgent-held eastern Aleppo by the end of the year. While the overstretched, undermanned and war-weary Syrian army has taken the lead, Russia has provided air cover and Iran has provided reinforcements on the ground.
On a local level, the trio have focused their firepower on key districts of the city’s eastern half and driven dominant al-Qaeda-affiliated jihadis and small rebel factions into 30 per cent of the area they seized in 2014.
The objective of the offensive is to rout insurgents before they can receive fresh weaponry and recruits and to prevent their allies based in the northwestern Idlib province from mounting a fresh rescue mission.
During two previous attempts to relieve the fighters in eastern Aleppo, al-Qaeda’s Jabhat al-Nusra and its partners took territory in the strategic Ramouseh industrial zone southwest of the city, but were ousted during bitter fighting.
Civilians on both sides of the city – the majority in the east where the toll has been higher than in the government-held west – are also war-weary and eager to end the conflict. The number killed in east Aleppo since the current offensive began in mid-November is said to be about 300. Several dozen have died in that time in west Aleppo.
Insurgent control
At least 50,000 have fled to government- or Kurdish-held districts. Others stayed at home when the Syrian army entered their neighbourhoods. Some 100,000 of the 250,000 who have resided in eastern districts are said to be in areas still under insurgent control.
The Aleppo offensive by Russia and Damascus appears to have been partly driven by frustration over the failure of Russian efforts to persuade insurgents to evacuate through corridors designated for this purpose, or to allow UN aid convoys to deliver food and medical supplies to an estimated 250,000 civilians in the east.
Russia has insisted that until the departure of Jabhat al-Nusra, which it deems a terrorist organisation, the campaign will continue.
Russian foreign minister Sergei Lavrov expressed Moscow's frustration when he warned, "The armed groups who refuse to leave eastern Aleppo will be regarded as terrorists. We will treat them as such . . . and will support a Syrian army operation against [them]."
At the international level, Russia and China have blocked UN Security Council resolutions designed to halt the fighting, while Lavrov has appealed, so far in vain, to Washington to agree to a political, rather than military, solution. Russia has also been encouraged to fight by the reduction in Turkish and Saudi support for insurgents, although Qatar has pledged to supply funds and arms to them.
Political cover
Damascus, Moscow and Tehran have strong reasons to resolve the Aleppo situation soon. The offensive is taking place in parallel with the US-backed Iraqi government's campaign to drive Islamic State from Mosul, which gives the Aleppo campaign a degree of political cover. The Iraqi onslaught follows the Aleppo pattern.
In Mosul, a million civilians remain in the city, bombardments have displaced 85,000, and fleeing men have been arrested by authorities seeking either anti-government fighters, in the case of Syria, or Islamic State fighters in Iraq. The parallels make it difficult to condemn the Syrian offensive while ignoring Mosul.
Although heartened by statements by US president-elect Donald Trump that he will discontinue the Obama administration's policy of regime change and arming insurgents, Moscow and Damascus could be concerned about his unpredictability and conflicting regional aims.
Trump’s promise to adopt a hard line towards Tehran could undermine his readiness to join forces with Damascus and Moscow to defeat Islamic State if this means Iran’s influence in Syria could be enhanced.
Trump’s plan
Trump's appointment of former general James Mattis as defence secretary could, however, allay concern as he does not favour Trump's promised withdrawal from the six-power deal for the dismantling of Iran's nuclear programme in exchange for lifting sanctions.
The war in Syria has provided Russia and Iran with the means to play major roles on the regional front. Neither is prepared to back away from the government of Bashar al-Assad, which they see as the only alternative to the fracturing of Syria into fiefdoms ruled by warring warlords.
For Russia, Syria has become a strategic stronghold in the region from which Moscow, which seeks global influence, has been excluded for decades by the US.
For Iran, eliminating Islamic State in Syria could ensure the radical Sunni group would not have a base from which to attack the pro-Iranian Shia fundamentalist Iraqi regime once the group has been defeated in Iraq.
Like Russia, Iran seeks a regional role despite fierce opposition from Saudi Arabia and its allies.