Once Syria's most populous manufacturing and trading hub, Aleppo has become a prize in the five-year war pitting the Syrian government against a disparate collection of insurgent factions. Aleppo .
Located 50 km south of the Turkish border, the city is strategically, psychologically and politically essential to all sides and became a battleground in July 2012 when insurgents belonging to local factions seized and based themselves in eastern districts.
Since then fundamentalist groups, including the al-Qaeda-linked Jabhat al-Nusra, have usurped control.
Aleppo's proximity to Turkey, which supported the rebellion against President Bashar al-Assad, enabled fighters, funds and weapons to flow into northern Syria. Without the Turkish connection, insurgents would not have been able to conquer Idlib province, now dominated by Nusra, the countryside north of Aleppo, and Raqqa, the de-facto capital of the Islamic State terrorist group.
During 2015 government forces encircled insurgent-controlled districts of the city and, in February 2016, the army captured roads and towns north of Aleppo, cutting insurgent supply lines.
The cessation of hostilities proclaimed on February 27th freed government troops from attacks by insurgents bound by the truce and enabled the army to isolate Nusra and Islamic State pockets around Aleppo.
The presence of Nusra and Islamic State, both of which were excluded from the ceasefire, allowed government forces to continue attacking them and allied insurgents, prompting two large factions, Jaish al-Islami and Ahrar al-Sham, to launch an offensive on government-held neighbourhoods. This elicited heavy retaliation and ended the truce in Aleppo province as a whole.
Both sides have been castigated for violating the ceasefire and attacking civilians and hospitals and US secretary of state John Kerry advised factions to cut ties with Nusra and Islamic State.
Psychological boost
Containing insurgents, Islamic State and Nusra in and around Aleppo has enhanced army morale on top of the considerable psychological boost given when last month government forces recaptured the town and ancient ruins of Palmyra and the Christian town of al-Qaryatain.
Morale among anti-government fighters seems to have slipped and the tide of recruits to Islamic State has, reportedly, fallen steeply.
Aleppo is also politically important to the warring parties. Since 2012 the city has been divided between government-held western districts, with 750,000 residents, and the insurgent-controlled eastern sector, with 250,000 inhabitants. For the warring sides control of people is as important as control of territory.
Although 1.5 million of its former citizens have fled to the capital, coastal cities, and abroad, Aleppo remains the second largest population centre in Syria after Damascus, where the population has swelled by multiples due to an influx of displaced people.
About 65 per cent of Syrians living in the country reside in government-held areas in Aleppo, Damascus, Latakia, Homs, Hama, and Deraa, granting Assad a measure of domestic legitimacy, which the opposition, allied insurgents and their external supporters have been unable to erode.
Therefore, the loss of Aleppo would constitute a major blow to the government, while regaining the eastern sectors of the city in a long-promised offensive would amount to a coup that could enable the Syrian army to take on Nusra in Idlib and Islamic State in Raqqa.
This is the last thing the insurgents, Nusra, Islamic State and their external supporters want and why they will try to use the ceasefire to freeze the situation on the ground in Aleppo and elsewhere.
Seeking to prevent this from happening, the government has agreed to a series of 24- and 48-hour periods of “quiet”, enabling Damascus to assert some control over when and where there will be fighting as well as humanitarian access to besieged and hard-to-reach areas where people are in dire need of food and medical supplies.