JOHANNESBURG — It sounds chilling: two of the world's most powerful extremist movements, one in the Middle East and the other in Africa, team up to spread their harsh brand of Islamic rule.
The quick acceptance by the so-called Islamic State of Boko Haram's pledge of fealty is a publicity boost, and comes at a time when both are suffering combat losses. Boko Haram militants in Nigeria and the Islamic State group in Iraq and Syria, 2,000 miles (3,200 kilometers) away, might declare joint operations, possibly using an IS affiliate in chaotic Libya as a bridge to move arms and fighters. But whether they can effectively do that is very much in question.
What is certain is that recent developments, including the newly declared alliance, have deepened the internationalization of the almost 6-year-old Nigerian conflict.
Multinational efforts to crush the West African militants echo the disparate array of forces, including U.S. air power and Iran-backed Shiite militias, which are fighting the Islamic State group.
Already, forces from Chad, Cameroon and Niger are waging an offensive against Boko Haram. On top of that, Nigeria acknowledged late Thursday that it is getting help from regional security operatives amid reports that South African and other foreign contractors are in the fight against Boko Haram.
One South African security contractor was killed during operations earlier this week in the Maiduguri area in northeast Nigeria, where Boko Haram is active, according to South African media. Nigeria has not commented directly on the role of any South African contractors, some of whom are believed to be veterans of the apartheid-era security forces. A number of those veterans worked for the now-defunct Executive Outcomes, a private military outfit from South Africa that played a role in conflicts in Sierra Leone, Angola and other African countries in the 1990s.
France said it will slightly increase its troop numbers by the end of the year in the Sahel, which includes the Lake Chad region where most of the fighting between Boko Haram and soldiers from Nigeria and neighboring countries is taking place.
"We do not intend to take part in the fighting," French Defense Minister Jean-Yves Le Drian said this week. France currently has 3,000 troops involved in Operation Barkhane, a campaign against Islamic extremists in the region.
The Islamic State group was quick to accept Boko Haram's allegiance on Thursday, in contrast to slower deliberation on the pledges of other militants, some of whom abandoned al-Qaida affiliates to do so.
Boko Haram's pledge stirred fresh debate about whether Islamic State is extending its global reach. Nigerian extremists have been weakened recently by the multinational force and the Islamic State group is also under pressure from Iraqi troops and allied Shiite militias that have swept into the Iraqi city of Tikrit.
One analyst downplayed the idea of "any kind of organizational linkage" between Boko Haram and the Islamic State group.
"These movements are trying to outdo one another in terms of radicalization and scare tactics," said Jakkie Cilliers, executive director of the Institute for Security Studies, based in Pretoria, South Africa.
J. Peter Pham, director of the Africa Center at the Atlantic Council, a research center in Washington, said increasing Western assistance to the multinational African military effort against Boko Haram and the role of South African and other contractors "make this fight all that more appealing to the Islamist extremists."
"Militants finding it increasingly harder to get to Syria and Iraq may choose instead to go to northeastern Nigeria and internationalize that conflict," Pham wrote in an email to The Associated Press.
Many militants have traveled to Syria through Turkey, which has pledged tighter border controls under international pressure. On Friday, it said authorities had detained 16 Indonesians who were trying to cross the border to join the Islamic State group.
Following Boko Haram's pledge, the Nigerian government may hope for more support from the United States and other countries, said Antony Goldman, a Nigeria analyst and head of London-based firm PM Consulting. Nigerian militants, in turn, could hope for "logistics, leadership and personnel," possibly from Libyan groups, he said.
Libya, which has an Islamic State affiliate, could provide a locale for joint training and operations planning.
The purported unofficial involvement of South Africans in the conflict in support of Nigeria's government could prove problematic when they return home.
South African media have quoted South African Defense Minister Nosiviwe Mapisa-Nqakula as saying earlier this year that those South Africans were "mercenaries" and should be prosecuted when they return home.
Nigerian government spokesman Mike Omeri denied that his government is engaging in "any backchannel or unlawful recruitment." He would only say that "individuals" from the region "are on the ground in a capacity limited to training or technical support."
Associated Press writers Zeina Karam in Beirut, Lebanon; Sylvie Corbet in Paris; and Michelle Faul in Nairobi, Kenya contributed to this report.