WASHINGTON — The US-led attacks that began late Monday against terrorist forces in Syria are equivalent to what a senior Pentagon war planner called buying time for ill-prepared allies on the ground to finish the job.
The strikes are designed to weaken the Islamic State’s hold on its Syrian sanctuary so that regional allies such as the Iraqi army and Syrian rebels can take back the large areas of both countries that are now under the sway of the radical Islamic group.
These stated limits of the US campaign underscore the extraordinary challenges facing President Obama as he seeks to sustain a broad coalition at home and abroad to defeat the militants without inserting American ground troops into the conflict.
The participation of five Arab countries in the Syria strikes was seen by specialists as a significant step in building that international coalition. It sends a clear signal that even the terrorists’ fellow Sunni Muslims see them as a threat and are prepared to confront them.
“It is very historic in terms of the support we got from five Sunni-led nations,” said retired Lieutenant General Richard Newton, the former assistant vice chief of staff of the Air Force, referring to Saudi Arabia, Jordan, the United Arab Emirates, Bahrain, and Qatar
Those overseeing the air campaign said the most crucial aspect will be ensuring that local forces in areas infiltrated by the Islamic State will build upon the airstrikes to take back their territory.
Lieutenant General William Mayville, director of operations for the Joint Chiefs of Staff, cited the role of Iraqi security forces, which were overrun in the face of the Islamic State’s assault over the summer, the Kurdish peshmerga militia, and Syrian rebels eager to receive American training and arms.
“The most important thing is to create some space for the Iraqi security forces to reorganize and . . . get on the offensive,” Mayville said at a Pentagon briefing.
Initial accounts suggest the new strikes by US and allied aircraft and Navy ships — on top of strikes over the last six weeks in Iraq — damaged or destroyed a series of facilities and forces that the Islamic State has built up during the course of Syria’s civil war, including communications systems, headquarters, training camps, weapons supplies, and barracks for fighters.
“This can be a tremendous boon to the ground forces who are there and who can engage the enemy,” said retired Air Force Major General Walter T. Givhan, former head of the Air University in Alabama and now a vice chancellor at Troy University.
Indeed, some of the local forces that the United States is counting on said that in the wake of the strikes, they were ready to follow up on the ground.
Hadi Al-Bahra, president of the Syrian Opposition Coalition, said in a statement Tuesday that his group would work “to ensure the military fight takes place on the ground, and to ensure that there is no need for US or foreign boots on the ground.”
Obama met Tuesday afternoon with a group that included representatives from the five Arab nations that participated.
‘‘The strength of this coalition makes it clear to the world that this is not America’s fight alone,’’ Obama said.
But a number of military specialists believe that it could take years for those ground forces to be in a position to fully capitalize on the damage that US air power can inflict on the Islamic State.
“Once the Iraqi army is reconstituted and motivated, it may take six to 12 months,” predicted Michael O’Hanlon, a military analyst at the Brookings Institution. “There is no reason to think that this war will be won soon.”
At the same time, Pentagon officials have said the Syrian rebels may not be armed and trained for up to a year — and even then may not be large enough or even willing to confront the Islamic State. Its primary enemy in Syria has been the regime of President Bashar Assad.
“The current plan appears to turn not on the participation of any American or allied ground units, but eventually on some 5,000 moderate Syrian rebels who will be trained over the next year,” Richard Fontaine, president of the Center for a New American Security, said Tuesday.
“This contingent, presumably backed by American air power, will be expected to combat up to 30,000 ISIS fighters while evading Bashar Assad’s air force,” Fontaine said.
Facing such tough odds might eventually increase the need for ground forces from the United States or elsewhere, he wrote.
Maintaining broader support in the region could also prove challenging, especially if the conflict lasts many months and exacerbates the humanitarian crisis in both Iraq and Syria.
The enlisting of several key Arab militaries — including dozens of other nations that have pledged financial and humanitarian assistance, in addition to the Arab nations that participated in the strikes — was seen as a key diplomatic victory.
A senior State Department official said the Arab coalition coalesced during a trip to the region this month by Secretary of State John F. Kerry, who considered it vital to get Saudi Arabia to participate.
Kerry failed to enlist Turkey in the airstrikes, even though it is a key US ally that shares the longest border with Syria and has been criticized for buying oil sold by the Islamic State.
Kerry said in a speech in New York on Tuesday that he remained confident Turkey would be “very engaged on the front lines.”
President Recep Tayyip Erdogan of Turkey, in New York for meetings at the United Nations, said Tuesday that he was considering expanding the support for Western and
Arab operations against the
Islamic State to include military involvement, the AP reported.
One key regional player not on the US list of allies is Iran, which is a Shi’ite Muslim country and has supported the Assad regime.
Iran does not have diplomatic relations with the United States and is not being treated as a partner even though it also sees the Sunni militants as a threat.