It’s not a question of combat power. The U.S. has plenty of local allies willing to fight ISIS there. The challenge is convincing those groups to fight the militants rather than each other.
“The biggest problem with Raqqa will be managing the coalition,” said J. Matthew McInnis, a Middle East security expert with the American Enterprise Institute. “If you get an extra six hundred or an extra one thousand troops, that doesn’t dramatically change the situation from a military standpoint, but it does from a political standpoint. You gain a certain amount of ability to manage the situation when you have a little bit larger number troops there.”
U.S. officials say the invasion of Raqqa will begin within weeks. They feel a sense of “urgency” because new intelligence suggests ISIS leaders in Raqqa are planning external attacks in the U.S. and Europe.
This will draw the U.S. military deeper than ever into the multi-sided Syrian civil war, a battlefield far more complex than the one in Iraq, which for years has been the main focus of the U.S. effort to defeat ISIS. The invasion of Raqqa will put the teams of U.S. special operations troops into a unique role managing the movements of rival allied factions that often have fought each other during the five-year-old conflict.
Small teams of American troops will attach to various allied elements, which could include the Turkish military, Syrian Kurdish militias, Sunni Arab tribal fighters and others linked to the so-called Syrian Defense Force, according to defense officials familiar with the planning.
Those teams of elite American troops will provide vital communication links between the groups as well as to the U.S.-led coalition’s centralized command and control system overseeing the operation.
“The U.S. can play a very pivotal role in negotiating this, and then the U.S. troops would help them deconflict it on the ground,” said Andrew Tabler, a Syria expert with the Washington Institute for Near East Policy.
“I don’t know who else can play that role.”
TURKEY vs. THE KURDS
The main fissure in the U.S. alliance is between Turkey and the Syrian Kurds.
The U.S. military believes that the only rebel faction capable of fighting ISIS in Raqqa is the Syrian Democratic Forces, or SDF, a network of militias dominated by the Syrian Kurds. Syrian Kurdish fighters have proven to be an effective ally for fighting ISIS with the help of U.S. air strikes in other parts of Syria.
Yet Turkey — a NATO ally — fiercely opposes U.S. support for the Kurds, fearing that a strengthened Kurdish force will consolidate power and form its own autonomous region along Turkey’s southern border. For decades Turkey has mounted counter-insurgency operations targeting its own restive Kurdish minority.
This tension erupted in combat recently. On Oct. 20, the two sides exchanged indirect fire, prompting the Turkish military to launch air strikes against Kurdish forces. Turkey said its attacks killed 160 to 200 Kurdish fighters.
The U.S. also depends on Turkey for use of Incirlik Air Base, a hub for U.S. air operations near Turkey's southern border. A power struggle has played out in public view as the top American general overseeing operations against ISIS vowed to march on Raqqa with Kurdish forces regardless of Turkey's opposition.
“Turkey doesn’t want to see us operating with the SDF anywhere, particularly in Raqqa,” Lt. Gen. Stephen Townsend acknowledged in a press briefing last week. But, he added, “we think there’s an imperative to get isolation in place around Raqqa because our intelligence feeds tell us that there is significant external attack planning going on” there.
“I think we need to go pretty soon,” Townsend said. “And I think that we’ll go with the forces that can go on the timeline that we need.”
Soon afterward, Turkish President Recep Erdoğan called President Obama and vowed to send Turkish troops to Raqqa. But it was unclear how much the Turkish military will coordinate with the American-led coalition, an ambiguity that has made the White House uncomfortable.
“We're mindful of how complicated this space is,” White House spokesman Josh Earnest said on Thursday. “It's important that [Turkey’s military] actions are well coordinated to prevent any sort of unintended consequence or unintended escalation among competing interests in that region of the world.”
The next day, Turkey's prime minister, Binali Yildirim, said its military will not participate in the U.S. operation to invade Raqqa if Syrian Kurdish fighters are included. Turkey, he said, would support the fight, "however, if groups we classify as terrorist organizations like the PYD and YPG are included in the operation, we will not be there." Those acronyms refer to the Syrian Kurdish militias backed by the U.S.
The U.S. and Turkey may resolve the matter in a way that makes the battlefield even more complicated, said McInnis. “The best case scenario for the U.S.," he said, "is to move toward some zones of operation, that we try to stay out of each other’s way.
"Having additional U.S. troops in Syria would help manage the balance of power and manage the situation with Turkey."
MORE U.S. TROOPS IN SYRIA
Townsend said the invasion of Raqqa will involve far fewer U.S. troops than operations in Iraq, where about 5,000 American personnel are currently deployed, many supporting the invasion of Mosul that began Oct. 17.
“We’re also trying to keep a footprint that is very light there to avoid worsening any of the complicating, pre-existing conditions,” Townsend said.
Yet Anthony Cordesman, a defense exerts with the Center for Strategic and International Studies, said the Raqqa operation's success will ultimately depend on whether the U.S. and its allies can muster enough combat power on the ground.
“If we do not have a decisive ground component, it is not enough to deal with a problem like Raqqa,” Cordesman told Military Times recently.
He suggested that the U.S. military could quietly surge hundreds of additional U.S. special operations troops into Syria without a public announcement by categorizing them as “temporary duty” personnel, a status officially known as “TDY.”
“TDY," Cordesman said, "is the magic acronym.”
The size of the American force may also have an important psychological impact on the fight for Raqqa's city center, said Bassam Barabandi, a former Syrian diplomat who now lives in Washington and advocates for Syrian rebels groups.
“The more Americans are involved, the more it will send a message that this is a serious fight," he said. "If people in Raqqa see that the American are coming, you are encouraging them to make revolution against [ISIS] inside the city."