Iraq, have dropped off drastically as the extremist group has come under military pressure, according to a study by terrorism researchers at West Point.
In addition, the researchers found, there has been a striking shift away from publications and social media portraying a functioning state with competent bureaucrats, thriving businesses and happy citizens. The Islamic State, also called ISIS and ISIL, claims that it is building a new caliphate — or unified Muslim land — a claim that has become increasingly threadbare.
“It’s not just the numeric decline,” said Daniel Milton, director of research at the Combating Terrorism Center at West Point and the author of the new report. “The caliphate was their big selling point. Now there’s an inability to say we’re doing the things that make us a state. And that was behind their broad appeal.”
At the peak of the Islamic State’s media output, in August 2015, the group released more than 700 items from official outlets in Syria and several other countries. During the month of August 2016, after a year of airstrikes and other assaults, that number had declined to under 200, according to the study.
Over the same period, the share of items devoted to military reports doubled to 70 percent, eclipsing attention to governance, commerce and other topics portraying civilian life.
The findings reflect a cascade of failures for the Islamic State, reversing its sudden rise both in territory seized and propaganda reach in 2014. Experts caution, however, that the Islamic State’s ideology, which portrays Muslims in an apocalyptic contest with non-Muslims, is likely to continue to inspire terrorist acts long after its caliphate is gone.
Beginning in 2014, Islamic State propaganda was effective not just because it was often sophisticated and well-produced, but because of its message of inevitable victory, urging Muslims around the world to join the successful state-building effort.
As long as the group was expanding by seizing cities and territory in Syria and Iraq, and later in Libya and elsewhere, that message resonated with some young Muslims across the Middle East and North Africa, in some European countries and, on a smaller scale, even in the United States.
But as the military campaign by the United States and its allies has shrunk the Islamic State’s turf and killed some of its leaders, it has started to look less like a religious state with a future and more like an eroding terrorist army.
In April, the Pentagon reported that the flow of foreign fighters into Syria had dropped from 2,000 a month to about 200 a month. In late June, Brett McGurk, President Obama’s envoy to the coalition fighting the Islamic State, said that the group had been driven out of nearly half the territory it had occupied in Iraq, and that the number of foreign fighters had dropped from 33,000 to about 20,000.
J.M. Berger, co-author of “ISIS: The State of Terror” and associate fellow with the International Centre for Counter-terrorism in The Hague, said that other researchers had witnessed the steady reduction in Islamic State media production.
“Everyone who watches this is seeing the drop-off,” he said. “They’re dropping the utopian sales pitch they started with. And that’s hurting their recruiting effort.”
The Combating Terrorism Center tracked the last two years of media output, looking only at visual products from sources considered “official” by the Islamic State: videos; posts on Twitter and elsewhere that include images; and what it calls picture reports — collections of photos and captions. Skipping text-only messages made the volume more manageable and put the focus on items with greater potential influence, he said.
Mr. Milton said he believed that most of the reduction in the Islamic State’s media output was a direct effect of the anti-Islamic State coalition’s military action, eliminating both facilities and authors. “The Islamic State’s media people are fighters, too,” he said. “And when they’re fighting, they can’t put out their message.”
Some killed in airstrikes are eulogized as “media martyrs,” he said. On Monday, the Islamic State released a eulogy for its “information minister,” Wail al-Fayad, who was killed in an American airstrike in Raqqa last month, according to the Site Intelligence Group, which tracks jihadist media.
The output may also have slowed because of efforts by social media companies, notably Twitter, to thwart the Islamic State’s use of their platforms. Since Twitter began aggressively suspending Islamic State supporters, the group has moved to Telegram and other sites, and the greater attention to evading measures taken against it has probably slowed its output, Mr. Milton said.
When its insurgent army first marched across Iraq in 2014 and riveted the world’s attention, the Islamic State’s prolific messaging was unexpected. Rather than calling on Westerners to stage attacks at home — as, for instance, Al Qaeda’s branch in Yemen had been doing — it invited them to move to the caliphate.
In one slick video, a Canadian recruit urged North Americans to bring their families to Syria. “Your families would live here in safety, just like how it is back home,” said the recruit, André Poulin. “You know we have expanses of territory here in Syria.”
Islamic State photo collections, posted to various websites, showed bustling commerce in Raqqa, the Syrian city it made its capital, and often sent a message of normalcy: factories humming, store shelves well-stocked, children swimming and playing. The message to those drawn by the notion of the caliphate was that they would find more than war — they would find a thriving, happy young state.
That began to shift in 2014 after the United States and its allies began airstrikes and the Islamic State publicized gruesome beheadings of journalists and aid workers. But the dual messaging of peace and war continued.
The peak of visual media production came in late summer 2015. Since then, as the air assault on the Islamic State in Syria continued and ground troops took back territory in Iraq, the group has found it difficult to sustain its promise of a functioning state ready to receive eager new arrivals.
The West Point study found an indication of distress even in the most gruesome media items: a decline in portrayals of executions of captured enemy fighters and a rise in items showing executions of Islamic State fighters accused of spying or treachery. The researchers believe the shift indicates more worry inside the Islamic State about infiltrators and a desire to deter those tempted to betray the caliphate.
While the decline in the Islamic State’s propaganda is good news for the effort to shrink and defeat it, it is unlikely to end the threat it poses. Most experts say the danger of terrorist attacks in the West is likely to rise as fighters in Syria abandon the battlefield there and return home, a phenomenon already seen in France and Belgium.
Mr. Milton, of the Combating Terrorism Center, said one disturbing, and still unpredictable, long-term question about the Islamic State relates to its internal propaganda, fed daily to millions of residents of territory it controls in Syria and Iraq. Many of those residents are children who have been indoctrinated with bigotry.
“How do you deal with all the children who have had these experiences and who have been exposed to this worldview?” he said. “This is going to be a long-term problem.”