The U.S. is planning to join a large-scale air and ground coalition offensive to free Mosul, Iraq, from the clutches of Islamic State militants in coming weeks, but analysts fear the effort will lack the resources to succeed — most notably U.S. boots on the ground.
The plan, part of a larger undertaking dubbed Operation Inherent Resolve, will be the first challenge for Defense Secretary Ashton Carter in trying to balance the expectations of the White House with the needs of the military. Many policy analysts say the choices Mr. Carter makes in the Iraq operation will be indicative of his style of leadership at the Pentagon.
In June, the Islamic State — also known by the acronyms ISIL and ISIS — took the northern city of more than 1 million people, Iraq’s second-largest, after waging a violent assault that prompted Iraqi police to flee their posts. The size of the Islamic State’s presence in the region was estimated to be as high as 14,000, although U.S. officials say they don’t have a good current estimate.
The U.S. military has spent months preparing for the large-scale operation, which will depend largely on the tactical strength of Iraqi security forces, Kurdish fighters, tribal police and warplanes belonging to various members of the 40-nation coalition, which includes Jordan and Britain.
International forces have been trying to isolate Mosul by cutting off communication lines between members living within the city and outside forces.
Pentagon officials say the effort to reclaim Mosul is likely to launch the spring, soon after Mr. Carter has been brought up to speed on the coalition’s strategy and operational needs.
An official for U.S. Central Command, which oversees military operations in the Middle East, told reporters Thursday that a force of 20,000 to 25,000 Iraqi security forces, Kurdish fighters and regional police will be tapped to defeat the 1,000 to 2,000 Islamic State militants who are camped out in Mosul.
That attack depends on whether international forces are able to quickly train Iraqi and Kurdish fighters. The military may change its plans if the delivery of pertinent combat equipment is delayed or if more training is needed, the official said.
“The mark on the wall that we are still shooting for is the April-May time frame,” the official said. “There’s still a lot of things that need to come together, and as we dialogue with our Iraqi counterparts, we want them to go in that time frame because if you get into Ramadan in the summer in the heat, it becomes problematic if it goes much later than that.”
Iraqi Prime Minister Haider al-Abadi told BBC News this week that Iraqi government forces were “planning an offensive on Mosul in the next few months,” with help from the U.S.
Mr. al-Abadi ruled out the need for U.S. ground troops in the campaign. He said his country needs other forms of help, such as weapons and training, and anticipates the city could be retaken in as little as a few months with minimal casualties.
In an unusual show of military strategic planning, the official laid out for reporters a detailed plan of the multipronged, international assault on Mosul.
“What we know as of right now is that in the attack force there will be five Iraqi army brigades,” the official said. “There will be three smaller brigades that will comprise a reserve force. There will be three [Kurdish fighter] brigades that will help contain from the north and isolate from the west, and then there will be what we’re calling a ‘Mosul fighting force,’ which will be comprised of largely police and tribals that are being put together right now of mostly former Mosul police. And then, finally, a brigade equivalent of counterterrorism service forces.”
Security analysts are not as optimistic.
The U.S. military has steadily led its partner nations in the region into a “onesie, twosie whack-a-mole” airstrike campaign that has had only incremental success, said Doug Birkey, executive director at the Mitchell Institute for Aerospace Studies in Virginia.
If the U.S. doesn’t alter its strategy and continues to conduct only a small cluster of airstrikes, then the Islamic State has a good chance of prolonging its reign in Iraq and Syria, Mr. Birkey said.
“If we just do very small operations in a low-level fashion, they have all the room in the world to adjust their approaches and they have elasticity,” he said.
In the past week though, multiple polls have found public opinion shifting on the matter of the Islamic State, even on the long-taboo matter of using U.S. ground forces.
A CBS News poll released Thursday reported that a 57 percent majority “favor sending ground troops into Iraq and Syria to fight ISIS.” That figure is up from a 47 percent plurality in October and a distinct minority of 37 percent in September, against a 55 percent majority opposed.
A Fox News poll released last week showed similar sentiment, with 60 percent saying the Islamic State could not be defeated without U.S. ground forces.
Pentagon officials have remained vague about whether U.S. special operations forces will be sent to Mosul to battle Islamic State militants alongside Iraqi government forces. Government officials say they expect the military will continue its trend of providing air support.
On Mr. Carter’s first day in office, Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, briefed him on the overall progress of the campaign against the Islamic State in Iraq and Syria, said Rear Adm. John Kirby, a Pentagon spokesman.
Although the Pentagon chief now has a broad view of the sprawling war, he has yet to speak with Gen. Lloyd J. Austin III, commander of U.S. Central Command, about specifics of the operation.
In advance of the planned counteroffensive, international troops are training 3,400 Iraqi security forces at five sites in Iraq. About 1,800 of those forces have completed six- or eight-week training courses, said Army Capt. John Moore, a spokesman for the Combined Joint Task Force.
International troops also have put hundreds of Kurdish fighters in northern Iraq on a fast-track course of about four weeks, according to military data.
Given Mr. Carter’s position, he may have limited input on the Iraqi operation, but his official stance will say much about how he intends to spend his time at the Pentagon, said Steve Bucci, a former Army Special Forces officer and top Pentagon official who is now at The Heritage Foundation.
If Mr. Carter aligns himself with Gen. Dempsey, who has suggested using special operations forces in Iraq, it would be significant because the White House has been reluctant to embrace that stance, Mr. Bucci said.
Others view the Iraq operation as a litmus test of whether Mr. Carter is willing to stand up to his boss.
“Mr. Carter is quite aware that as the Obama administration’s fourth defense secretary, he can afford to be more vocal about his opinions and throw his weight around in the political wrestling pen,” said the Mitchell Institute’s Mr. Birkey. “He’ll be able to go to the mat a little more aggressively, because it would not be politically opportune to go find another secdef.”
Mosul often has been a thorn in the side of U.S. operations. During the Iraq War, the U.S. military dubbed it the last stronghold of al Qaeda in Iraq. The city also served as an entry point for Syrian fighters.
The U.S. military eventually took control of the city and set up an operational base to provide stability. In 2004, insurgents tried to retake the city, leading to a suicide attack that killed 14 U.S. soldiers, four U.S. contractors and four Iraqi soldiers. Mosul has been war-torn ever since.
Many of the city’s Sunnis faced discrimination from Iraq’s Shiite-controlled government and welcomed Islamic State invaders last summer. After taking control of the city, the terrorists seized vast arsenals of U.S.-supplied arms and ammunition and hundreds of armored vehicles.
The U.S. hasn’t had combat troops in the region since 2010, when the final team crossed the Iraq border into Kuwait.