Something major is brewing in northwest Syria.The Assad regime has been back on the attack in recent days. The fighting is focused on the area of Aleppo, Syria’s second-largest city. Russian air strikes and regime artillery are backing up the troops of President Bashar Assad’s army as they push back the rebels in northeastern Aleppo province.Meanwhile, as regime forces pressure the rebels of Jabhat al-Shamiyya (Levant Front) from the south, seeking to encircle Aleppo city, Islamic State fighters are attacking them from the north.The fighting in Aleppo province comes alongside a renewed regime push forward in northern Hama province.In Aleppo, the initial goal of the regime forces is the long-standing one of encircling Aleppo city. The regime then intends to push on to link up with the two besieged Shi’a villages of Nubl and Zahra. If this is achieved, the ability of the rebels to supply their beleaguered forces in Aleppo city from across the border in Turkey via the route south from Azaz will be terminated.The regime advances represent a reversal of the trend in the war since the beginning of 2015.The current fighting, however, appears to be merely a prelude to an upcoming, much larger offensive.Energetic preparations are under way in the regime stronghold in Latakia province.The intention of this offensive will be to end the long and bloody back-andforth in northwest Syria by finally destroying the rebel holdings in Idlib and Aleppo provinces. If this goal is achieved, the area of regime control will then border Islamic State at its western edge.Russian air power is set to play a key role in the fighting in northwest Syria. Largescale bombing has already taken place in Idlib and Hama provinces.The key issue in the coming battles, however, will be the ground component.Assad’s main disadvantage throughout the civil war has been the absence of a sufficient number of men willing to engage on his behalf.It was this shortage of men that led to the withdrawal from much of northern Syria in 2012, which he and his allies are now trying to reverse. The Syrian dictator proved unable to replenish the losses from among his own people. And, in contrast to his Sunni Islamist opponents, there was no pool of ideologically motivated volunteers from the region and beyond it interested in coming to serve under his banner.But the long-standing regime alliance with the Islamic Republic of Iran has played the key role in preventing this key deficiency from turning to disaster. Iran has throughout proved willing to mobilize its key regional proxies, bringing in fighters from Hezbollah and from the Shi’a militias of Iraq to fight on the ground for the regime. In addition, the Iranians have trained new formations of Alawi paramilitary forces for Assad, giving him a ground component more reliable than the largely Sunni conscript army.It appears that Iranian support will be crucial in the upcoming offensive as well.According to a report in the Kuwaiti Al-Rai newspaper, 2,000 members of the Iranian Revolutionary Guard Corps have arrived in Latakia, along with 2,000 Iraqi Shi’a militiamen, 2,000 Afghan Shi’a fighters and 1,000 men from the elite forces of Hezbollah.These men are set to be deployed in the fighting in Idlib and Aleppo in the period ahead.Will Assad’s offensive succeed? This depends on how success is defined. The rebels are not helpless. The major forces of Jaish al-Fatah (Army of Conquest) have yet to fully engage. And where engagements have taken place, there have already been some setbacks for the regime. A number of armored vehicles were lost to the rebels’ BGM-71 Tow antitank missile systems in the fighting in north Hama. Supplies are still coming in for the rebels from across the Turkish border. Qatari, Saudi and Turkish support is still there. The regime/Russian/ Iranian side will face a determined and well-motivated foe.Russian and Iranian assistance nevertheless looks likely to succeed in ending the immediate threat to the integrity of the regime enclave in Latakia. It is also possible that the gains made earlier this year by the rebels in Idlib and Aleppo provinces will be reversed. Perhaps the strategic town of Jisr al-Shughur and Idlib city and even Aleppo city will return to regime hands.But the fundamental problem for the regime, which has beset it since the beginning of the war, will then resurface: how to hold these areas, where the Sunni Arab population absolutely rejects the regime.The Assad regime may have surprised some with its vigor, but after four years of bloody civil war, the rebellion, too, shows no signs of running out of steam – or out of fighters.So unless the Iranians are willing to maintain a more or less permanent occupation of northern Syria, using proxies or even their own men, in the face of ongoing Sunni jihadi resistance, it is difficult to see how Assad can hold, in the long term, what he may conquer in the period immediately ahead.Still, as of now, the IRGC men and the Iraqis are arriving at the Basel Assad International Airport in Latakia. Quds Force commander Qasem Soleimani is in the country, coordinating preparations on the ground. Hezbollah reinforcements are crossing in from Lebanon. Assad’s autumn offensive appears to be about to begin.