BEIRUT -- A two-pronged advance to capture key urban strongholds of the Islamic State group and its self-styled capital of Raqqa, Syria, has underlined a quiet convergence of strategy between the U.S. and Russia to defeat the extremists, with Syria's Kurds emerging as the common link.
The dual advance toward Raqqa by the Syrian army from the southwest and the predominantly Kurdish Syria Democratic Forces from the north and west puts further pressure on the militants as they fend off simultaneous attacks in neighboring Iraq on bastions such as Fallujah, and potentially Mosul. The Kurdish involvement is proving vital to the interests of Washington and Moscow.
For the U.S., the predominantly Kurdish Syria Democratic Forces has proved the most capable group in northern Syria in defeating the extremist group, a point it made when its predecessor, the Kurdish YPG, held off the militants in Kobani in 2015. That battle was seen by many as a turning point in the war on the Islamic State group.
For Russia, the Syria Democratic Forces advance has drawn Islamic State fighters away from the front with the Syrian government and allowed the Kremlin's allies in Damascus to advance, showing that Moscow is participating in the battle against the Islamic State group.
While the media has focused on the battles between Iraqi government forces and Islamic State militants in the city of Fallujah, west of Baghdad, the Syrian army on Saturday reached Raqqa province for the first time in almost two years. The Syrian government has had no presence in Raqqa since August 2014, when the Islamic State group overran the Tabqa air base and killed scores of government soldiers in a massacre they documented on video. The provincial capital, Raqqa, became the militants' first captive city.
Backed by intense Russian airstrikes, Syrian troops began their advance toward the province Wednesday, the same day that U.S.-backed Syria Democratic Forces launched an attack on the Islamic State stronghold of Manbij, which is 72 miles northwest of Raqqa and lies on a key supply route linking Raqqa with the Turkish border.
"In terms of direct coordination of activities on the ground, that is not happening," Pentagon press secretary Peter Cook said. "I know there have been discussions about changing that, but at this point, our position is the same."
Asked about it Monday, President Vladimir Putin's spokesman, Dmitry Peskov, told reporters, "We exchange information with the United States on a daily basis, twice a day, that's all I can say."
U.S. officials have consistently said that there are frequent conversations about flight-safety matters and daily phone-line checks to make sure the two nations can communicate quickly when necessary.
Lina Khatib, head of the Middle East and North Africa program at the Chatham House think tank, said it was hard to imagine such dual attacks on the Islamic State happening without prior agreement between the U.S. and Russia. Cooperation between the two global powers, which back opposing sides of the war, has marked the Syrian conflict in recent years.
"The Syria Democratic Forces is playing a complementary role to the [Syrian] army, and that is the product of a military agreement between Russia and the U.S. that is translating into a division of labor between the two forces on the ground," Khatib said.
Syria's Kurds, who make up 10 percent of Syria's prewar population of 23 million, have played an outsize role in the civil war, now in its sixth year. The U.S. has struggled from the beginning to find moderate, effective partners in the chaos of the conflict, and the largely secular and cohesive YPG -- the armed wing of the Kurdish PYD political party -- has emerged as Washington's most trusted associate.
The Syria Democratic Forces -- a mixed-religion anti-Islamic State coalition made up of Kurdish and Arab groups -- is dominated by the YPG. The U.S. provides critical air support to the Syria Democratic Forces, and hundreds of U.S. special operation forces help train the group. Russia has also offered support to the Kurds, partly to gain leverage over Turkey, which considers the PYD to be a terrorist group.
The situation is similar to the offensive on Fallujah in Iraq, where the Iraqi army works alongside Shiite militias against the Islamic State.
Neither the Syrian nor Iraqi army has the capacity to be the sole actor in the battle against the Islamic State, and their external backers have incorporated the presence of others to provide military support.
The Syria Democratic Forces denies coordinating with the Syrian government. But such dynamics are partly why the group is viewed with suspicion by other Syrian actors and the local population in Arab-majority areas.
Bassma Kodmani, a member of a Syrian opposition group known as the High Negotiations Committee, said it is perplexed by the Syria Democratic Forces's political position, saying the group sometimes attacks the Syrian army and sometimes fights on the same side.
"We have a player here that it's not at all clear what they stand for, what they want, what their ultimate agenda is -- none of this is clear to us," Kodmani said. She added that such opacity creates outright hostility.
The perceived coordination between the Syria Democratic Forces and the Syrian army is a potential problem for the United States because the Syrian government forces get more emboldened by each military victory against the Islamic State.
"The Obama administration is keen to demonstrate some form of achievement against the Islamic State before the end of the president's term, and in a way it seems that the focus on military achievement is overshadowing what happens the day after," Khatib of the Chatham House think tank said.
Raqqa is frequently targeted by the U.S.-led coalition, as well as the Syrian and Russian air forces.
The battle for Raqqa is expected to be long and hard, with Syrian troops still about 45 miles away. Very few expect any real push toward the city soon.
The government is making a "low-cost investment" to position itself near Raqqa and "message its involvement in the [Islamic State] campaign, to bolster its international credibility," said Christopher Kozak, a Syria analyst at the Institute for the Study of War. The Syria Democratic Forces has not been able to recruit enough Arab fighters, and the Kurds would rather focus on liberating areas in the Raqqa governorate that border Kurdish regions.
A Raqqa resident who fled there recently said the militants have dug trenches and planted mines around the city in anticipation of an attack. The resident, who spoke on condition of anonymity for fear of his safety, said the militants were well-prepared for what they perceive to be a "decisive battle," whether with the Syria Democratic Forces or army troops.
Information for this article was contributed by Bassem Mroue, Josh Lederman, Lolita C. Baldor and Nataliya Vasilyeva of The Associated Press.
A Section on 06/07/2016