ALEPPO, Syria — The regime’s Aleppo campaign has reached a new crescendo, with the controversial barrel bombing taking center stage in what is essentially a drive to depopulate the rebel-held east of the city. It's a horrific tactic that kills and maims innocents, and such indiscriminate heavy bombing may amount to a war crime. The battle has begun in earnest, although any anticipated all-out assault has so far failed to materialize. Instead, it is a careful, drawn-out and tactfully planned operation, seizing upon changing factors both on and off the battlefield — stalled peace talks in Geneva and rebel infighting.

Regime forces, bolstered by local militias such as the Quds Battalion, drawn from the Nayrab Palestinian refugee camp, and the National Defense Forces (NDF), comprised mainly of local Sunni tribes as well as foreign militias such as Hezbollah and the Iraqi Shiite Abu Fadl al-Abbas Brigades, have been making slow but steady gains in their campaign to recapture the city and surrounding towns, skewering vital links to rebel-held territories in the north and the northeast along the Turkish border.

The momentum in Aleppo has shifted decisively in favor of the regime recently, and it is no secret that the Syrian government came perilously close to losing the city on several occasions, most notably when it seemed powerless to stop rebel advances into new territory in the west, or lift the crippling siege that cut off the only means of resupply via the Damascus highway and the Khanaser military route.

But a series of events, some planned and others merely a stroke of good fortune, saw the rebels’ momentum reversed and their grip slowly loosen. The man credited with turning the tide in the regime’s favor is Brig. Gen. Suheil al-Hasan, aka Nimer (Tiger), head of military operations in Aleppo, and the mastermind behind the barrel-bombing strategy. His string of victories began with securing the Khanaser military route, thereby releasing the rebel stranglehold on west Aleppo, and culminated in the decisive recapture of the strategic town of Sfireh. The capture of this town paved the way for regime forces to advance into east Aleppo and other strategic areas around the city, turning the table on the rebels, who were by now heavily bogged down by their own feuds, infighting and corruption.