BEIRUT, Lebanon, May 8 (UPI) -- The long anticipated final assault on Raqqa, Syria, de facto capital of the steadily crumbling Islamic State caliphate, is looming as U.S.-backed forces steadily isolate it and prepare to storm the heavily fortified city.
The main battle will likely be fierce and costly in a city that Syrian rebels captured in March 2013 and proclaimed the first "liberated" provincial capital. IS took control of Raqqa in January 2014 and began its reign of terror.
There are an estimated 3,500 militants in Raqqa, along with a shrunken civilian population of about 200,000 held hostage by the jihadists.
Since the first moves to attack Raqqa began in the autumn of 2016, the city has been hammered by U.S.-led airstrikes. Raqqa has been gradually cut off by U.S.-led Kurdish and Arab fighters of the Syrian Democratic Forces, the Americans' main proxy, that now numbers 50,000 fighters. They have severed most main roads into the city, blocking food supplies.
The Britain-based Syrian Observatory for Human Rights, which monitors the conflict through a network of activists throughout Syria, and sources inside Raqqa says hunger is becoming acute. Much of the city is in ruins, primarily because of the airstrikes that began in September 2014.
By April, the SDF, backed by U.S. special forces with U.S. Marine Corps artillery units and U.S. Army Rangers, had encircled Raqqa on three sides and was within a few miles of the outskirts.
As its citadels in Syria and Iraq have been stormed one after the other over the last two years IS has shown that it fights to the death and gives no quarter. Airstrikes and artillery fire have reduced large tracts of those cities to ruins.
The Iraqi military's battle to retake Mosul is instructive. It has dragged on into its seventh month and about half the city is still in IS's hands. Iraqi losses have been heavy — an estimated 6,000 dead or wounded — and much of the city has been destroyed.
Raqqa is much smaller than Mosul but IS's dogged defense of the Tigris River city suggests that casualties on both sides in Raqqa are likely to be heavy. There is little doubt that Raqqa, like Mosul, will eventually fall, driving IS from its last urban strongholds in Syria and Iraq.
The big winner in all of this is likely to be the Assad regime, which, after its victory in driving rebels out of Aleppo in December, courtesy of Russia and Iran, controls all of Syria's major cities.
Whether the Americans will hand control of a reconquered Raqqa to the regime or leave it in the hands of the Kurds, who seek eventual independence from Damascus, remains unclear.
U.S. President Donald Trump may find it difficult not to deliver the city into Syrian President Bashar al-Assad's hands rather than trigger a Kurdish-Turkish war in northern Syria that would likely be the harbinger of Syria's disappearance as a unitary state.
According to IHS Jane's Terrorism and Insurgency Center, it is Assad's forces rather than U.S.-backed ones that are doing most of the fighting against IS. The London-based publication reports that about 43 percent of IS's clashes were against Assad's forces, while only 17 percent involved American-supported groups.
Jane's concludes that if Assad is ousted, the big winner would be IS, effectively nullifying jihadists' looming loss of Mosul and Raqqa.
Columb Strack, senior Middle East analyst with IHS, observed: "It is an inconvenient reality that any U.S. action to weaken the Syrian government will inadvertently benefit the Islamic State and other jihadist groups.
"The Syrian government is essentially the anvil to the U.S.-led coalition's hammer. While U.S.-backed forces surround Raqqa, the Islamic State is engaged in intense fighting with the Syrian government around Palmyra and in other parts of Homs and Deir ez-Zor provinces."
As the noose tightens on Raqqa, the biggest wild card in the arcane Syrian war is Turkish President Recep Tayyip Erdogan, who, now that he has been handed immense power in Turkey's April 16 constitutional referendum, might feel emboldened to take military action to prevent Raqqa falling into Kurdish hands. If Syria's Kurds captured Raqqa, Erdogan would see that as a step towards eventual Kurdish statehood.
Preparations for the final assault on Raqqa suffered a potentially serious setback April 25 when Erdogan launched airstrikes against Kurdish fighters of the U.S.-backed People's Protection Units, the main component of the SDF, in northeastern Syria, killing at least 20 men. Ankara said the attacks were aimed at cutting off supply lines to Turkey's outlawed Kurdistan Workers' Party, which has waged a separatist insurgency since 1984.
But the strikes were widely seen as Erdogan venting his anger against the YPG, which Turkey sees as the PKK's Syrian arm.
Turkey opposes the United States using the YPG to spearhead the assault on Raqqa, whose population is predominantly Arab, but the Americans consider the Kurdish fighters to be the most capable and reliable ally they have in Syria and refuse to allow Turkey to pursue its own strategic objectives.
Erdogan has warned there may be more airstrikes, indicating a possible clash between the NATO allies in yet another of the dangerous twists and ever-shifting alliances for which this war has become notorious.
This article originally appeared at The Arab Weekly.