The appeal of the Islamic State militant group to citizens of the United States is diminishing, with fewer Americans making the journey to join them, according to Federal Bureau of Investigation Director James Comey.
The comments came Wednesday during a wide-ranging discussion with reporters, when Mr. Comey contrasted the "6, 8, 10" Americans who traveled, or attempted to travel, each month during 2014 and the first half of 2015 to the Middle East to join the self-styled Islamic State, with a sustained downward trend that now averages just one a month.
"There's no doubt that something has happened that is lasting, in terms of the attractiveness of the nightmare which is the Islamic State to people from the United States," said Comey.
While the FBI director himself offered no explanation for the change, one possibility is a shift in the tactics of IS, encouraging more devotees to stay at home and carry out attacks on their own soil. Comey did acknowledge that the group's potential for inspiring "troubled souls" remains a persistent concern.
In fact, his agency has "north of 1,000 cases" in which evaluation is still seeking to determine the subjects' level of radicalization and their propensity to carry out acts of violence.
The FBI has also determined that the December San Bernadino, Calif., attack that killed 14 people was inspired by the Islamic State. The husband and wife who carried out the slayings, Syed Farook and Tashfeen Malik, were themselves killed by police in a gun battle, but the case went on to inspire months of wrangling between the FBI and Apple, as the federal agency sought to unlock Mr. Farook's iPhone to assist its investigation.
"There's still a presence online, and troubled people are still turning to this and at least being interested in it," Comey said. "But they've lost their ability to attract people to their caliphate from the United States in a material way."
The other likely factor in the decline is the aggressive efforts of the FBI itself over the past year to identify Americans determined to reach Syria, and to frustrate those plans.
While the drop in numbers may pay homage to those efforts, the methods used have courted criticism as well as compassion. Particularly controversial has been the use of undercover agents to coax those suspected of an interest in committing acts of terrorism into taking material steps towards that end.
To some, "such techniques smack of entrapment," as Warren Richey wrote in an article on the subject last fall for the Monitor.
"When you set up a 17-year-old kid and you go and you wire your informants and you rile him up and then you catch him in the act, you've lost the trust of an entire community with that one stupid act," Yasir Qadhi, a leading Islamic scholar in the US and a professor at Rhodes College in Memphis told Mr. Richey.
Supporters counter that these law-enforcement operations are taking place amid a backdrop of a sophisticated and methodical recruitment effort by the Islamic State organization that seeks to radicalize receptive individuals in any and every corner of America.
"Because there is a threat of a firearms attack on a train tomorrow, or on a shopping mall or a school, you don't have the luxury of sitting back and just collecting intelligence," William Braniff, executive director of the National Consortium for the Study of Terrorism and Responses to Terrorism at the University of Maryland, told the Monitor.
"The law enforcement community and the professional counter-terrorism community are in this very difficult position," he said.
But in spite of disagreements over the methods, Comey's latest statistics offer some reassurance to Americans, bringing a welcome sign of progress in a situation that has cast a long shadow in recent years.
This report contains material from the Associated Press.