The survival of Somali al Qaeda affiliate al Shabaab is a chilling precedent

Last week's terrorist attack in Garissa, in eastern Kenya, is the deadliest single massacre ever committed by the Somali al Qaeda affiliate al Shabaab. The murder of 147 people at a university was the bleakest possible evidence that there is no target al Shabaab considers off-limits.

In exacerbating the 2011-2013 Somali famine, Shabaab - which at that point controlled far more of the fractious Horn of Africa country than it does currently - contributed to a disaster that ended up killing over 260,000 people by blockading humanitarian relief. The large-scale and mostly-invisible atrocity was on a scale that not even ISIS and Bokko Haram have been able to match yet.

The university attack also shows certain discontinuities with Shabaab's recent past. A few years ago, Shabaab controlled the Somali capital of Mogadishu and attracted foreign fighters from all over East Africa. Today, it's a terrorist group with a remote safe-haven that actually exports violence to Somalia's neighbors.

The Garissa attack doesn't prove that Shabaab is getting more brutal - it was always one of the world's most depraved armed groups. This isn't even the first time it's attacked a university - Shabaab bombed a medical school graduation ceremony in Mogadishu in 2009.

Nevertheless, the attack shows that in the absence of territorial control, Shabaab is inflicting its violence wherever it can while pushing its network outwards.

"Even a small insurgency, transformed, makes for a huge terrorist capability," analyst JM Berger wrote in a blog post shortly after the Garissa attack. And Shabaab has transformed itself in a very specific way, using methods that, as analyst Clint Watts argued in a World Politics Review article shortly before the attack, could become a model for ISIS once it loses its territory.

Shabaab has remained dangerous despite the loss of much of its territory and top leadership, including the domineering Ahmed Godane and more recently Adnan Garaar, Shabaab's head of external operations and the mastermind of the September 2013 Westgate Mall attack in Nairobi.

As Rahma Dualeh, a senior consultant with the Nairobi-based think tank Sahan Research and an expert in security in the Horn of Africa explained to Business Insider, Shabaab has a large contingent of foreign fighters and multiple partner groups inside of Kenya. And it's created an atmosphere of terror in Somalia in places that it doesn't still control, ensuring that it maintains enough influence to hold on to its safe-haven well into the foreseeable future.

Noor Khamis/Reuters

A Kenya Defense Force soldier keeps residents at bay to prevent them from moving in the direction where attackers are holding up at a campus in Garissa April 2, 2015.

Shabaab's foreign network

Dualeh said that there are enough entrenched Shabaab-linked local groups in Kenya to make it counter-productive to look at terrorism as a problem emanating solely from the Somali side of the border. It's a local problem that observers and experts still don't fully understand. As Dualeh puts it, "It's difficult to identify who the 'them' is" when looking at terrorism in Kenya."

Is it Al Hijra, the shadowy underground extremist network that may extend into neighboring Tanzania? Is it the separatist Mombasa Republican Council, or the jihadist Muslim Youth Council, long considered to be a Kenyan extension of Shabaab influence?

Shabaab may have also have sleeper cells around with the Horn, with some yet-unknown operational relationship with local groups. Dualeh recalled Shabaab's March assassination of a lawyer prosecuting suspected Shabaab terrorists in Kampala, the typically tranquil capital of Uganda and site of a major Shabaab attack in 2010. The event raised the ominous possibility that Shabaab was more present in the region's population centers than many would like to believe.

"Definitely we have to consider the possibility of sleeper cells in places we might not have been thinking of, like in Kampala or Dar el-Salam [Tanzania's capital]," Dualeh says.

Complicating matters is Shabaab's success in drawing foreign recruits. Shabaab originally formed to fight a multinational African force that dislodged the fundamentalist Islamic Courts Union from power in Somalia in 2006. There are large, marginalized Somali minorities in Ethiopia and Kenya, and a very small but nevertheless worrying number of Somalis in neighboring countries traveled to Somalia to resist what some of them viewed as a foreign, Christian occupation of their homeland.

Those fighters now have a network that can help them carry out attacks inside their countries of origin - as Dualeh noted, the suspected head of al Hijra is believed to be responsible for representing Kenyan Shabaab fighters in Somalia.

Grievances in Kenya ...

Kenya has a large Somali and Muslim minority that's long suffered from various forms of political and economic exclusion. A still-ongoing Kenyan invasion of southern Somalia in 2011, along with a string of terrorists incidents inside of Kenya, have led to spiking ethnic tensions along with heavy-handed responses from the country's security services.

"Mass arrests are coming down hard on the Somali population of Kenya," Dualeh explains. The government has tried to deflect criticism by presenting its terrorist problem as a purely external matter - while also associating legitimate domestic critics with the country's security issues.

"People who are talking about economic and political inclusion are being labeled as terrorists," Dualeh says, saying that the government is trying "to make their narrative easier" by associating regional or ethnic autonomy movements in the country's northern and eastern regions with the Shabaab threat.

Tensions are particularly high in Kenya's northeastern province, an impoverished and desertifying border area with a large Somali population, and a region still hosting large numbers of refugees from Somalia's famine.

This atmosphere of political and ethnic tension has exploded in the past, during riots targeting Kenya's Somali community in 2012 and an anti-Somali backlash in the wake of the Westgate shooting.

This gives Shabaab's network a recruitment opening, while fosters a general sense of uncertainty and panic in which the region's worst actors could thrive.

... and an atmosphere of terror in Somalia

Shabaab hasn't ruled over Mogadishu for over 3 years. But the group is still present and has footholds in the displaced persons camps that ring the city. Shabaab also killed over 20 people, including a top-ranking diplomat, in an attack on a Mogadishu hotel just days before the Garissa massacre.

Even if post-conflict investment is pouring in and Somalia has its most stable government in a generation, Shabaab is a potent physical and psychological presence and provide a dispiriting lesson in how a much-diminished terrorist group can exercises power just by lurking in the shadows.

For instance, the school system in Mogadishu runs off of Shabaab's schedule for off-days and holidays rather than the government's, years after the group last ruled the capital. And Shabaab still exacts taxes from travelers and transport companies entering and leaving the capital, even if they work with relief organizations.

"In Somalia it's becoming increasingly more difficult for them to maintain ground, but just because they don't maintain ground doesn't mean they don't maintain influence," says Dualeh.

"They're coercive in nature even though Shabaab's not physically there," she adds, speaking of the Somali capital. "It's going to be a long time before we see people carrying out their business without the fear of Shabaab."

A chilling precedent

Shabaab has foreign fighters, entrenched and covert foreign networks, and a dangerous psychological advantage over its targets.

Total victory over the group is going to take advances against the group in Somalia, along with concurrent shifts in Kenya's internal dynamics. And it'll take a return to normality in Shabaab-effected regions that might take years or even decades to fully affect.

Shabaab shows that even groups that lose the strategic initiative for years at a time can remain deadly so long as they can exploit local grievances and keep their networks intact.

The loss of promising, young life in Garissa is both an unfathomable tragedy, and a warning as to how illusory conventional victories over terrorists groups can be. ISIS may lose its territory in the Middle East one day.

But if Shabaab is any precedent, the world will have swapped the group's vast territorial control for a set of perhaps more manageable yet even murkier and even less readily solvable problems.