Skip to main content

U.S. official: ISIS 'credible alternative to al Qaeda'

By Barbara Starr, CNN Pentagon Correspondent
August 15, 2014 -- Updated 0230 GMT (1030 HKT)
  • The Islamic State, also known as ISIS, is expanding its presence, official said
  • Fighters loyal to ISIS could number more than 10,000 with some returning home countries
  • Law enforcement is watching a small number of Americans for possible affiliation
  • The U.S. is watching to see if ISIS loses support from other Sunnis

(CNN) -- The Islamic State terror group is now "a credible alternative to al Qaeda" that is "expanding its presence" with foreign fighters returning from Syria, and possibly Iraq, to their home countries, a U.S. intelligence official said Thursday.

The official, who declined to be identified due to the sensitive nature of the information, has direct knowledge of the latest intelligence on the group, also known as ISIS or ISIL.

According to an assessment, the group has grown in size since the spring and its takeover of Mosul in northern Iraq as more fighters from around the world have mainly traveled to Syria to join its ranks.

The United States believes that while the group remains largely focused on its brutal takeover of large areas of Iraq, there is also an "expansion of its external terrorist ambitions."

A Yazidi family from Sinjar cleans a spot for themselves in a derelict building that houses more than a thousand other refugees on Thursday, August 14, in Zakho, Iraq. A Yazidi family from Sinjar cleans a spot for themselves in a derelict building that houses more than a thousand other refugees on Thursday, August 14, in Zakho, Iraq.
Iraqi refugees fleeing ISIS
Iraqi refugees fleeing ISIS Iraqi refugees fleeing ISIS
Pro-ISIS leaflets distributed in London
Yazidis take refuge from ISIS militants

Some foreign fighters are returning to their home countries with orders to "start new cells" of terrorist activity, the official said.

What to know about ISIS

While some members may have a desire to attack the United States, the group's leadership is still focused on establishing an Islamic caliphate.

Still, they "see conflict with the United States as inevitable," the official said.

The United States believes a deadly shooting at Belgium's Jewish Museum in May by an alleged ISIS loyalist may be the kind of attack that could happen more often in western countries, possibly including the United States.

U.S. law enforcement is watching a small number of Americans for possible affiliation with the group.

How ISIS is overshadowing al Qaeda

ISIS foreign fighters may be operating somewhat independently of the organization's hierarchy, which the United States believes maintains lines of authority and even succession plans.

The intelligence community is now updating its assessment of how many fighters may be loyal to the group, and the number could be more than 10,000, the official said.

ISIS has taken advantage of the momentum it gained in Iraq over the past several months, resulting in a large number of new fighters joining up.

Inside the ISIS militant operation

Map: Where is ISIS?

While it currently has funds from taking over oil facilities and other operations in Iraq, the United States believes that will not be enough to sustain ISIS if it tries to seize the entire country, the official said.

The United States also is watching closely to see whether and at what point ISIS loses support from Sunni loyalists in Iraq.

The U.S. calculation is that ISIS is taking advantage of its recent momentum. Because it is seen as "successful" in many areas, including Yemen and Africa where al Qaeda affiliates operate, they have gained support from some jihadists more widely.

Who is the ISIS?

In those areas, they also remain at odds with the core of al Qaeda in Pakistan led by Ayman al-Zawahiri and several of affiliates.

The thinking is as momentum slows, ISIS will be "under more pressure, reality sets in," the official said. "We don't see the group as 10 feet tall."

Part of complete coverage on
Get all the latest news and updates on Iraq in Arabic by visiting CNN Arabic.
August 21, 2014 -- Updated 0350 GMT (1150 HKT)
The beheading of American journalist James Foley by ISIS militants brings into focus once again the risks faced by reporters in modern conflicts.
August 21, 2014 -- Updated 1720 GMT (0120 HKT)
When war reporter James Foley wasn't writing for GlobalPost or recording video for AFP, he occasionally shared stories on his own blog, aptly titled "A World of Troubles."
August 20, 2014 -- Updated 1517 GMT (2317 HKT)
A video released by ISIS shows the beheading of U.S. journalist James Foley and threatens the life of another American if President Obama doesn't end military operations in Iraq.
August 15, 2014 -- Updated 2134 GMT (0534 HKT)
"May God help you," the speaker of Iraq's parliament told Haider al-Abadi the day he was nominated prime minister.
August 15, 2014 -- Updated 0219 GMT (1019 HKT)
The answers to this question lie in some clear differences in the two conflicts.
August 14, 2014 -- Updated 2227 GMT (0627 HKT)
Framing the intervention in religious terms bolsters theories of U.S. bias, says Fahad Nazer.
August 18, 2014 -- Updated 1314 GMT (2114 HKT)
They are the faces of an entire community on the run.
August 17, 2014 -- Updated 0854 GMT (1654 HKT)
In an exodus of almost biblical proportions, thousands trudge across a river to escape killers belonging to the Islamic State in Iraq and Syria, or ISIS.
August 20, 2014 -- Updated 1313 GMT (2113 HKT)
Theirs were the faces that stood out in the chaotic helicopter evacuation off the Sinjar Mountains.
August 14, 2014 -- Updated 0013 GMT (0813 HKT)
Browse through photos of thousands of refugees trudging across a river to escape ISIS.
August 16, 2014 -- Updated 1541 GMT (2341 HKT)
The face of 15-year-old Aziza -- rescued from Mount Sinjar in Iraq -- says it all.
August 11, 2014 -- Updated 1850 GMT (0250 HKT)
CNN's Ivan Watson flies along with the Iraqi military as they drop emergency supplies.
Why do the militant Islamists have the Yazidis in their cross hairs?
December 19, 2014 -- Updated 1850 GMT (0250 HKT)
Images illustrate the ongoing violence in Iraq.
August 13, 2014 -- Updated 1608 GMT (0008 HKT)
The message from a growing number of actors inside and outside Iraq is the same: Maliki must go if the country is to be saved.
August 11, 2014 -- Updated 1523 GMT (2323 HKT)
ISIS gives young men "cars to drive, guns, cell phones and cash money."
August 16, 2014 -- Updated 1015 GMT (1815 HKT)
Which is worse: Running desperately for your life, or seeing others' lives end without enough to eat or drink?
August 12, 2014 -- Updated 1701 GMT (0101 HKT)
The Sinjar Mountains have always been a special place of refuge for the Yazidis.
August 9, 2014 -- Updated 1910 GMT (0310 HKT)
Will the U.S. air strikes increase the terrorist threat in the U.S. and Europe?
August 9, 2014 -- Updated 0251 GMT (1051 HKT)
Which religious and ethnic groups are under threat from ISIS militants?
ISIS has spread from Syria into Iraq. Learn where the militant strongholds are.
July 9, 2014 -- Updated 0156 GMT (0956 HKT)
'Why do these people kill other people?" For Iraq's youngest residents, the tragedy is almost incomprehensible.
Even those who aren't in the line of fire feel the effects of the chaos that has engulfed Iraq since extremists attacked.