海角大神

After the self-proclaimed Islamic State swept in from Syria in 2014 and grabbed huge swaths of Iraq, counterterrorism experts said the group鈥檚 control of significant territory would make it considerably more difficult to defeat.

Now switch continents. In Africa, the Nigerian Islamist extremist group Boko Haram has been losing control of a growing slice of the territory it held just a year ago. The Nigerian military is pushing the group out of towns and villages it once controlled, and the impact of drought and the group鈥檚 own scorched-earth strategy is forcing uprooted Boko Haram militants to surrender.

If Islamic State鈥檚 land grab made it more difficult to dislodge, does it follow that Boko Haram鈥檚 loss of territory in northeastern Nigeria is weakening the terrorist group 鈥� and potentially putting it on the road to defeat?

Some counterterrorism experts say yes. What's more, they add that recent events in Nigeria hold a broader lesson: Denying terrorists territory is an聽鈥渆ssential first step鈥澛爐oward defeating them.聽

鈥淏oko Haram is significantly weakened from where it was a year ago, and a key factor in that is the loss of territory it鈥檚 suffered,鈥� says Daveed Gartenstein-Ross, a terrorism expert at the Foundation for the Defense of Democracies in Washington. 鈥淎t this point they can still carry out devastating attacks,鈥� he adds, 鈥渂ut without secure territory to operate from, they are increasingly vulnerable to these mounting setbacks.鈥�

Boko Haram fighters have been entrenched in country鈥檚 northeast for years 鈥� which made photos of hungry and emaciated Boko Haram militants surrendering to government officials last week all the more striking. The fighters appeared to be the victims of their own actions. The group鈥檚 terrorizing forced farmers to flee, abandoning fields and crops. A drought has exacerbated conditions and added to spreading food insecurity.

The group has torched dozens of villages and murdered thousands of civilians 鈥� in particular 海角大神s and schoolboys getting what the group considered to be a 鈥淲estern鈥� education and who refused to join the terrorist organization. It is best known for kidnapping more than 270 schoolgirls in 2014 and enslaving the girls or forcing them into marriage with fighters.

Holding territory is key to the longevity and expansion of extremist groups like Boko Haram because it provides a steady stream of food and other sources of financial support. For example, the Islamic State financial model has changed as cross-border oil sales have become less secure, Mr. Gartenstein-Ross notes, now focusing on taxation of local populations.

Territory also provides a base at which to train fighters, build bombs, and from which to launch attacks. The importance of denying violent extremist groups a secure base of operation was underscored by two very different operations in the past few days: one by the United States targeting an Al Shabab terrorist base in Somalia; the other by Islamist militants聽attacking Tunisia from a safe haven in Libya.

In Somalia, air strikes on Saturday killed more than 150 fighters, the Pentagon said. Al Qaeda-affiliated Al Shabab has recently targeted African Union troops in Somalia on a peace and security mission.

In Tunisia, the Monday attack on a small border post raised new alarms about the threat posed by Islamic State-affiliated militants in eastern Libya. No one has claimed responsibility for the attack, but it followed a pattern of recent assaults launched from camps inside Tunisia.聽聽聽

US concerns about the expanding hold the Islamic State has on parts of Libya were evident in a US air strike Feb. 19 on a militant training base just across the border from Tunisia.

Control of territory is a key feature of more established 鈥� and more dangerous 鈥� violent extremist groups, says Gartenstein-Ross. There is an organizational spectrum that ranges from 鈥渢errorist group鈥� to 鈥渋nsurgency鈥� to 鈥渋nsurgency plus,鈥� with the last referring to a group is also a 鈥済overning force,鈥� he adds.

The Islamic State is in that last group. Boko Haram was in the process of getting to that level, Gartenstein-Ross says, but appears not to have been able to consolidate that role before being hit with a series of setbacks.

鈥淏oko Haram鈥檚 control and use of its territory hadn鈥檛 matured,鈥� he says. 鈥淭hey were positioning themselves to strengthen their hold but that has been cut short before they could take root.鈥� As a result, the group that was on its way to being an 鈥渋nsurgency plus鈥� in Borno state 鈥渘o longer is,鈥� he adds.

That does not mean Boko Haram is near becoming a defeated terrorist group. The US is planning to send several dozen Special Operations advisers to assist the Nigerian Army. And US officials warn that the group will continue to pose a significant threat to the region.

Boko Haram鈥檚 loss of territory is a 鈥渇irst step鈥� to defeating the group, Gartenstein-Ross says, but ending its threat will still take time. 鈥淚鈥檇 still say it鈥檚 a matter of years鈥�these groups tend to be resilient,鈥� he says. 鈥淏ut denying them their [territorial] base is still an essential first step.鈥�