The White House is holding an international summit this week to shore up domestic and global support to fight “extremists,” but who those extremists are is difficult to say.

The high-level summit, which was announced in the wake of the terrorist attacks in Paris, features three days focused on countering the growing threat of radicalization and recruitment efforts of extremist groups, and includes speakers from three pilot programs focused on “countering violent extremism” that were conducted in U.S. cities last year. International heads of state and senior officials from France, Jordan and Egypt, among other countries, are attending.

The summit is part of a broader administration strategy called “Countering Violent Extremism” (CVE), which is aimed at identifying and preventing radicalization.

Yet in a hastily arranged pre-summit call with reporters on Monday, senior administration officials speaking on background struggled to describe the purpose of the summit, or the Department of Justice program behind it. The officials provided few details on what to expect at the conference — from strategy and guest list to goals and new policy initiatives, if any.

They even had trouble naming a specific extremist group the administration was focusing on. “The message at the White House and the agenda itself is not entirely focused on ISIL itself,” an official said. “ISIL is the near term threat you all are focused on, but we also recognize that in the United States there have been violent extremists that come in all shapes and sizes and so the agenda for all three days is going to show speakers and participants from all backgrounds to combat radicalization, extremism and terrorism.”

Yet the only other extremist group the official was willing to name was the FARC, the Marxist guerrilla group in Colombia.

“I think it’s wrong for us to say that there’s any one stereotype that’s going to fit here and I think that it’s a mistake to have a government that’s focused on stereotypes,” an official said on the call.

The clearest message came Tuesday, in an op-ed by Barack Obama published in the Los Angeles Times.

“In Syria and Iraq, the terrorist group we call ISIL has slaughtered innocent civilians and murdered hostages, including Americans, and has spread its barbarism to Libya with the murder of Egyptian Christians,” President Barack Obama wrote in an op-ed published Tuesday. “In recent months, we’ve seen deadly attacks in Ottawa, Sydney, Paris and Copenhagen.”

Obama, who is scheduled to speak Wednesday afternoon at the summit, also singled out the Taliban in Pakistan, al-Shabaab in Somalia, and Boko Haram in Nigeria as examples of “violent extremists.”

All of the groups named by Obama in the op-ed are Muslim.

“We know from experience that the best way to protect people, especially young people, from falling into the grip of violent extremists is the support of their family, friends, teachers and faith leaders,” Obama wrote in his op-ed.

However, dozens of documents on CVE obtained by The Intercept show a nascent CVE program more confused than focused. The documents, some of which are marked “For Official Use Only,” offer a glimpse into the vast network of CVE-associated programs and activities involving federal, state and local authorities.

The documents and reports underscore the difficulties of combating radicalization, and at times admit that identifying those at risk may be illusory.

“We found no characteristic or pathway that was unique to domestic terrorists; many characteristics and behaviors of those individuals who radicalize to violence are found in the general population, which limits their utility as indicators of violent extremist activity,” noted one Department of Homeland Security report, dated May 2014 and titled “Domestic Terrorists: Common Characteristics of Paths to Violence.”

Among the best measures of identifying someone who may be plotting a terrorist act, according to the report, are obvious signs, like stockpiling weapons.

Although some of the documents suggest that measures to alleviate poverty would help prevent extremism, that May report notes that “[w]hile unemployment figured prominently among a number domestic terrorist study subjects, their socio-demographic characteristics were similar to the general population in education, economic status, family status, and rates of mental illness.”

If spotting “violent extremists” is difficult, so too is treating them. Another 2014 report by the National Counterterrorism Center, titled “Turning Points in Violent Extremist Disengagement” suggest that “[p]sychotherapy and emotional support from social workers and probation officers,” can help extremists turn away from violence.

That report, which described a five-step model for deradicalization, also suggests focusing “energy on something positive,” and providing “positive feedback” for those who leave radical groups.

Photo: Farah Abdi Warsameh/AP