The Syrian army, backed by allies Iran and Russia, is preparing for a military offensive to retake the country’s last major rebel stronghold —the province of Idlib. The battle could bring an end to a seven-year-old uprising-turned-civil war, but at the cost of a humanitarian disaster on a scale yet unseen in the bloody conflict. Some 3 million civilians are trapped in Idlib, along with tens of thousands of opposition fighters, including hard-core militants. In recent days, Syrian and Russian warplanes stepped up bombings, targeting the southern edge of the province and signaling a slow start to the campaign. Here’s a look at the issues involved: WHO IS IN IDLIB? Idlib is located in the northwestern corner of Syria. It is ringed by Turkey to the northwest, the Turkish-controlled Afrin region to the northeast and government-controlled territory to the southwest and southeast. A vital highway linking the cities of Aleppo and Damascus, known as the M5, cuts through Idlib’s eastern flank. The province fell into rebel hands in early 2015. It is now home to a dizzying array of opposition fighters, Islamic militants and jihadis. An alliance known as Hay’at Tahrir al-Sham, spearheaded by al-Qaeda affiliates formerly known as the Nusra Front, dominates the province. Another rebel umbrella group called the National Front for Liberation is backed by Turkey. An estimated 50,000 rebels, including more than 10,000 hard-core militants and al-Qaida-linked fighters, are cornered in Idlib. With nowhere left to go, some might opt to fight till death rather than surrender. Turkey also maintains a troop presence — hundreds of soldiers deployed at 12 observation posts in Idlib. Syrian government forces have massed to the south and southwest of the province. WHY IS IT A POTENTIAL CATASTROPHE? An estimated 3 million people live in Idlib, nearly half of them having arrived there after being displaced by fighting elsewhere in Syria. Among the civilians are close to 1 million children, according to rights groups. The province saw its population swell drastically as rebels and civilians were being sent there from other opposition strongholds after they capitulated to government forces. A full-scale air and ground offensive is likely to send waves of refugees surging toward the sealed Turkey border, coinciding with the onset of winter. A top UN official has warned that an attack on Idlib could lead to this century’s worst loss of life. Even a partial offensive focusing on specific areas of Idlib could displace hundreds of thousands of people and cut off aid access to the province. Most aid currently enters through the Bab al-Hawa crossing with Turkey. WHAT HAPPENS IF CHEMICAL WEAPONS ARE USED? UN investigators have previously attributed several chemical attacks in Syria to government forces, including one attack using the nerve agent Sarin gas against the Idlib town of Khan Sheikhoun in April 2017. In the run-up to a possible Idlib offensive, the Syrian government and Russia have alleged that rebels in Idlib are planning to use chemical weapons to frame the government and induce Western punitive airstrikes. Published in Daily Times, September 14th 2018.