Al-Shabab has been around for years as a militia group fighting for territory in Somalia.
When al-Shabab militants, dressed in casual clothes, turned up in a ritzy shopping mall in Nairobi, Kenya, last weekend and gunned down men, women and children, the group shifted from an insurgent movement to a terrorist organization.
"A week ago, al-Shabab wasn't in the news," says Bruce Hoffman, a a terrorism expert at Georgetown University and the Rand Corporation. "Arguably, outside of Somalia, no one really cared about them."
Yet the group has dominated the headlines this week. "They've been successful in staging an enormously bloody terrorist event," Hoffman says, "and it's catapulted itself back into prominence as one of the major terrorist forces in the world today."
That's prominence as a terrorist force, not an insurgent force. That was the old al-Shabab, the one defeated by the Somali military and African Union forces with U.S. support. Under pressure, it's been transformed. No more fighting head-on, trying to hold territory. Instead, it's allied with al-Qaida and dedicated to global jihad.
A Changed Al-Shabab
Al-Shabab is much leaner than it once was, says Katherine Zimmerman, who has been following al-Shabab as an analyst at the American Enterprise Institute.
"Many of the individuals who were there purely to fight an insurgency have peeled away," Zimmerman says. "So what we have now is a strong contingent of individuals who are in al-Shabab because it is an al-Qaida affiliate."
The attack at Nairobi's Westgate mall was not the group's first; three years ago, al-Shabab suicide bombers struck Uganda during a World Cup final. That attack was controversial within al-Shabab. Some of the group's more traditional leaders opposed it. Those leaders, Zimmerman says, have since been purged.
"The leadership is now united in conducting these sorts of attacks abroad in a way that it wasn't three years ago," she says.
An Act Of Strength, Or Desperation?
The Westgate attack showed that al-Shabab now has significant capability as a terrorist group, but does that make it stronger? Not necessarily, says Andrew McGregor, a terrorism analyst with the Jamestown Foundation.
McGregor thinks the Kenya attack showed al-Shabab's decline, not its re-emergence, though he acknowledges he holds the minority perspective.
"My view is that al-Shabab has really taken kind of a desperate stand here with this kind of attack," McGregor says. "Knowing that there will be inevitable retaliation, possibly ending the existence of al-Shabab as an organization, and even more probably ending the existence of much of its leadership."
McGregor thinks the United States, Kenya and other governments will now be even more determined to go after al-Shabab. He doesn't see the Westgate mall attack bringing the group more outside support. A lot of its income, McGregor says, has come from Somalis abroad the diaspora.
"I think a lot of the diaspora community is not going to look very favorably on this, because now Somalis will be viewed in these other foreign countries as potential security risks," he says.
A Fight That Crosses Boundaries
Examples from other countries may be useful here. Georgetown University's Hoffman compares al-Shabab with the group al-Qaida in Iraq. That group once controlled territory in Iraq, and it was beaten back. Lately, though, it has carried out attacks in Syria.
"We thought as well that al-Qaida in Iraq was crushed in 2009, 2010," Hoffman says. "But it merely reinvented itself as a terrorist organization, and one could argue is now even more formidable and more consequential. Much like al-Shabab, it's operating on a transnational playing field."
Counterterrorism officials do point out that al-Shabab, like al-Qaida in Iraq, is fighting a regional struggle. Despite the big attack in Kenya, they say al-Shabab is not yet seen as threatening the U.S. homeland.