U.S.-Backed Push on Islamic State's Raqqa Stronghold Begins

(Bloomberg) -- U.S.-backed forces in Syria have begun the long-anticipated push to remove Islamic State from its self-declared capital of Raqqa, a city the jihadist group has brutalized since 2013, and used as a base to plot terrorist attacks in Europe.

The Kurdish-led Syrian Democratic Forces and its partners launched their offensive on Tuesday, the U.S. Central Command said in an emailed statement.

“The fight for Raqqa will be long and difficult, but the offensive would deliver a decisive blow to the idea of ISIS as a physical caliphate,” the statement cited Lieutenant General Steve Townsend as saying. “It's hard to convince new recruits that ISIS is a winning cause when they just lost their twin ‘capitals' in both Iraq and Syria.”

Islamic State is also under assault from U.S.-backed Iraqi forces and allied militias in Mosul, Iraq's second-largest city. That effort has bogged down in street-by-street fighting for months, with civilians fleeing the fighting or trapped in the conflict.

The Syrian force said in a statement that its fighters' “morale is high and their readiness to implement the military plan is complete.” It urged Raqqa's youth to join SDF ranks as they advanced to help “liberate their city.”

The U.S. has been arming Syrian Kurds ahead of the assault, over the objections of NATO ally Turkey. The Turkish government considers the Kurdish separatists to be a terrorist group and says it's worried that the arms will be used to support Turkish Kurdish militants who have been battling for autonomy for more than three decades.

Islamic State declared a caliphate straddling parts of Syria and Iraq after capturing first Raqqa and then, in June 2014, Mosul. Since then, extremists linked to the group have proliferated and murdered hundreds in London, Ankara, Beirut, Brussels and Paris as well as in Iraq, Syria and elsewhere. 

Read More: Why Trump's Arming of Syrian Kurds Riles Turkey: QuickTake Q&A.

Retaking Raqqa would be a strategic victory for forces battling to roll back the group's territorial gains, though it won't be sufficient to halt terrorist attacks, according to Sami Nader, head of the Beirut-based Levant Institute for Strategic Affairs.

“When Raqqa falls it will be the end of ISIS geographically, but not of ISIS ideologically. It will usher in a new model, such as guerrilla warfare,” Nader said by phone. “You cannot fight an ideology with boots on the ground.”

Raqaa will provide a difficult test of President Donald Trump's order for the U.S. to pursue what Defense Secretary Jim Mattis has called a tactical shift “from shoving ISIS out of seized locations in an attrition fight to surrounding the enemy in their strongholds so we can annihilate ISIS.” Critics have said this “annihilation” strategy risks increased civilian casualties.

Before he was killed in a U.S.-led coalition air strike last year, Islamic State spokesman Abu Mohammed al-Adnani said in an audio message that loss of territory wouldn't weaken its supporters' willingness to fight. “Do you think, America, that defeat is the loss of a city or land?” he said.

The Syrian Democratic Forces already scored a small advance, overrunning a building and a checkpoint used by Islamic State fighters just outside Raqqa in the Mashlab neighborhood, the U.K.-based Syrian Observatory for Human Rights said in an emailed statement.

Civilians have been encouraged to leave the city so that they don't become trapped and used as human shields, or become targets for Islamic State snipers, according to the U.S. statement said.

--With assistance from Dana Khraiche and Caroline Alexander

To contact the reporter on this story: Donna Abu-Nasr in Beirut at dabunasr@bloomberg.net.

To contact the editors responsible for this story: Alaa Shahine at asalha@bloomberg.net, Stuart Biggs, Larry Liebert