Al-Nusra is "much more dangerous to the U.S. than the ISIS model in the long run," according to the authors of a report labeling both groups "existential" threats. The report was released last week by the Institute for the Study of War and American Enterprise Institute.
The report criticizes the administration's ISIS-centric strategy, saying, "Any strategy that leaves Jabhat al-Nusra in place will fail to secure the American homeland."
However, the chief of staff of the U.S. Army, Gen. Mark Milley, in a speech Wednesday said that only Russia constituted a potential "existential" threat due to its possession of a large nuclear arsenal capable of striking the U.S.
The report argues that ISIS and al-Nusra attacks could threaten the global economy and provoke "Western societies to impose severe controls on ... freedoms and civil liberties," thereby endangering "American values and way of life."
The report's authors include Fred Kagan, considered an architect of the 2007 "surge" strategy in Iraq, which increased American troops and engagement with local tribes to stabilize that country, and Kim Kagan, a former adviser to Gen. David Petraeus on Afghanistan strategy and the president of the Institute for the Study of War.
Though for now al-Nusra hasn't undertaken attacks in the West like ISIS has, Kagan said it's just as potent.
"While ISIS is flashier ... both represent an existential threat, both wish to attack the homeland, both seek the mobilization of Muslim communities against the West," she said.
In fact, Kagan warned that al Qaeda's Syrian branch represented a longer-term and more intractable threat than ISIS and that targeting al-Nusra would be more difficult than targeting the other group, both of which take advantage of the chaos of the Syrian civil war to expand their reach.
"Al-Nusra is quietly intertwining itself with the Syrian population and Syrian opposition. ... They are waiting in the wings to pick up the mantle of global jihad once ISIS falls," she said.
Peace talks between the regime of Bashar al-Assad in Syria and select rebel groups are tentatively scheduled to begin this month in Geneva, Switzerland, with the United States hoping that a resolution to the conflict will curtail the power of ISIS and other terror groups.
Al-Nusra, like ISIS, won't be participating in the talks, but the report argues that al-Nusra is "a spoiler that will almost certainly cause the current strategy in Syria to fail."
The State Department has said that over 35,000 foreign fighters from 100 countries have traveled to Syria to participate in the conflict and that the al-Nusra Front attracts the second-most foreign fighters, ranking only behind ISIS, according to Nick Heras of the Center for a New American Security.
Al-Nusra emerged in late 2011 during the early days of the Syrian civil war and was initially largely made up of battle-hardened Syrians who had traveled to Iraq to fight U.S. troops during the American engagement there.
It has emerged as one of the most effective groups fighting the Syrian regime and currently controls swaths of northwestern Syria. The group holds "coercive power" over several opposition groups, serving as a sort of "kingmaker," Heras said.
Al-Nusra does "not have the same capacity as ISIS, but its greatest usefulness is as a base of operations" to other elements of al Qaeda that may seek to strike Western targets," Heras said.
The Director of National Intelligence James Clapper in January 2014 told the Senate intelligence committee that al-Nusra "does have aspirations for attacks on the homeland."
However, in the DNI's 2015 threat assessment report
to the Senate Armed Services Committee, al-Nusra is listed under regional threats and not named in the global threats section. The State Department's 2014 Country Reports on Terrorism also labels al-Nusra a threat to "the Syrian opposition, Syrian civilians, and other states in the region."
Kagan said she believes al-Nusra has made a tactical decision not to attack the West for the time being.
"Right now, al-Nusra has decided not to overtly host attack cells because the al Qaeda leadership's priority is preserving success in Syria and avoiding being targeted by the U.S.," she said.
But she explained that the report still treated it as a larger threat than ISIS because, "We define a threat as having the capability and the intent. ... The capability is already there, and in time the intent will be as well."