Two men play music as a crowd gathers to celebrate in Ankara, on Jan. 27, 2015, after Kurdish forces retook the Syrian border town of Kobane. (Adem Altan/AFP/Getty Images)

The Obama administration hopes to capi­tal­ize on the defeat of Islamic State fighters in the Syrian town of Kobane as part of its uphill effort to counter the group’s appeal to foreign fighters from around the world.

The administration says that a significant number of foreigners — pushed to the front lines by the Islamic State — were killed in the town on the Turkish border. That is a message it wants to send to potential new recruits.

“You’re not going to be part of something that great, you’re not going to have a house, you’re not going to have a female slave,” a senior State Department official said Tuesday.

“If you’re an 18-year-old disaffected guy” looking for ad­ven­ture in the “recesses of the Internet . . . what was glory and conquest is now hundreds of bodies in the streets of Kobane,” the official said.

The hard-won victory by combined Kurdish forces and U.S. air power has encouraged American and European governments girding for the possibility of domestic terrorist attacks from citizens who return home after fighting with the Islamic State in Iraq and Syria.

“Kobane has broader ramifications” in countering the sophisticated Internet and social-media campaign by the group that has lured thousands from the United States, Europe, the Arab world and as far afield as Australia, the official said.

Foreign fighters arriving in Raqqa, the militant headquarters in north-central Syria, were fed to the Kobane front with promises of triumph, he said. But as new recruits saw that many of their comrades in arms did not return from battle, they started to refuse deployment.

As a result, a number of them “were executed” by the Islamic State, said the official, who described such militant “fratricide” as a growing phenomenon in Raqqa and elsewhere. The official spoke on the condition of anonymity under rules imposed by the State Department.

Such assertions are impossible to verify. An article posted Friday on the “Raqqa Is Being Slaughtered Silently” Web site, run by a clandestine group of Syrians inside the city, reported the Jan. 19 execution of two Saudi fighters who had sought the return of their passports.

As a result, the report said, “dozens of immigrants, mostly carrying Saudi nationality, have left.” Islamic State forces, it said, launched a “full alert” and began searching for them in the surrounding countryside.

The author of the story, reached via Skype, said that “there are a lot” of foreign fighters who “refused to go” to Kobane but that reports they were being executed for it were “mostly false.”

The Washington Institute’s Aaron Zelin, a specialist in jihadist movements who closely monitors events in Syria, said he had not heard “anything about people refusing to go fight in Kobane” or being executed, although “I have heard of people who have tried to leave and go back home.”

“Unless they’re willing to put out something publicly” in terms of intelligence or other information, Zelin said of the administration, “I have to be skeptical.”

The administration has said “counter-messaging” and discouraging foreign fighters are key elements of its campaign against the Islamic State. The State Department official, who initiated a discussion with reporters on what he called “fratricide within the ranks,” was asked whether the discussion was part of the administration’s own propaganda campaign.

“Sure. I think it’s important to point out what’s happening beneath the surface. . . . Foreign fighters are increasingly not following orders. . . . It wasn’t happening before Kobane,” the official said.

In late September, after the militants first surrounded and then moved on the Kurdish town, sending up to 200,000 of its inhabitants fleeing, the United States expanded its then-nascent air attacks elsewhere in Syria to include modest strikes on the outskirts of Kobane. But officials repeatedly characterized Kobane as a “sideshow” to the larger battle against the Islamic State underway in neighboring Iraq.

Fighters in other U.S.-backed Syrian opposition groups complained that the Kobane strikes showed the Americans were far more interested in protecting besieged Kurds than Syrian Arabs who were being slaughtered by the Islamic State and the government of Syrian President Bashar al-Assad.

By late October, as Kurdish defenders were on the verge of defeat, the Islamic State was clearly claiming Kobane as a major symbol of its strength. In response, the administration first conducted an airdrop of supplies to the encircled defenders and then negotiated with Turkey to open its border to Kurdish reinforcements and heavy weaponry. Airstrikes were gradually increased, and the sideshow became a major U.S. priority.

The Islamic State “wanted to raise the largest flag they ever had over Kobane,” the senior State Department official said. “They knew the international media was watching.”

Kobane had also become a prime militant selling point on social media. In a five-minute, professionally produced video released Oct. 27, a British journalist held hostage by the militants took viewers on a tour of the supposedly vanquished city. The battle for Kobane was “nearly over,” hostage John Cantlie said in the tones of a broadcast correspondent. “The mujahideen are mopping up now, street to street, and building to building.”

The video was one of a series featuring Cantlie, who was seized by the militants in 2012.

By early this year, Kobane had become the main Syrian target for airstrikes by the United States and its Arab partners. By last weekend, when U.S. officials said the Islamic State forces­ were retreating, 705 of a total of 954 strikes — the vast majority of them by U.S. warplanes — had targeted Kobane and its environs.

But while “forward momentum has been halted in Kobane,” the State Department official said, the Islamic State has shown itself to be “resilient and adaptive. It doesn’t mean anyone is saying mission accomplished” in the larger war against the militant force.

Asked whether the Kobane operation would serve as a template for retaking other Islamic State-held areas, particularly in Iraq, the Pentagon’s press secretary, Rear Adm. John F. Kirby, said that “every situation is going to be different.”

“Kobane is not Mosul,” the second-largest city in Iraq, whose conquest began the Islamic State sweep through that country early last summer, Kirby said.

But, he said, it shows that air power, along with “the presence of a reliable, willing, capable power on the ground,” can be effective.