Photo: Jerome Delay/AP Photo

A deadly ambush in Niger, an alleged murder in Mali. What are American troops doing in West Africa in the first place?

At about 11:30 in the morning on October 4, 12 members of a U.S. Special Operations Task Force and the 30 Nigerien troops they were accompanying were ambushed south of the village of Tongo Tongo near the Niger/Mali border by as many as 50 members of what the Pentagon believes to be an Islamic State-affiliated militant group.

The soldiers were attacked with small arms, RPGs and tactical vehicles—pickup trucks mounted with machine guns, according to a press briefing given by Chairman of the Joint Chiefs of Staff Marine Corps General Joe Dunford. Roughly an hour into contact, the team requested air support. An unarmed U.S. drone was overhead within minutes, and an hour after the call French Mirage jets screamed onto the scene. The small and under-armed force had been battling the militants for two hours before the jets arrived.

Later, French helicopters—which evacuated the wounded—and more Nigerien forces arrived. One Nigerien soldier told CNN that when he arrived, he found the surviving U.S. and Nigerien forces fighting in a defensive position—back to back—surrounded by smoldering bush, potentially set by the militants to deter air support. It is a striking image, and one that may come to define the West African region known as the Sahel.

These images provided by the U.S. Army show, from left, Staff Sgt. Bryan C. Black, 35, of Puyallup, Wash.; Staff Sgt. Jeremiah W. Johnson, 39, of Springboro, Ohio; Sgt. La David Johnson of Miami Gardens, Fla.; and Staff Sgt. Dustin M. Wright, 29, of Lyons, Ga. All four were killed in Niger, when a joint patrol of American and Niger forces was ambushed by militants believed linked to the Islamic State group. U.S. Army via AP

A desolate, poor and sparsely populated area that includes the nations of Burkina Faso, Chad, Mali, Mauritania and Niger, the Sahel is a region of West Africa south of the Sahara Desert that has been battling an influx of armed Islamic groups for years, spurred in part by the removal of Muammar Gaddafi and the subsequent destabilization of Libya.

The October 4 ambush that saw four American soldiers and five Nigeriens killed in Niger and the stunning allegations that another Green Beret, staff sergeant Logan Melgar, may have been strangled by members of SEAL Team 6 in an altercation involving the skimming of informant money in Mali have turned a spotlight onto the American military presence in West Africa.

So, why are American soldiers operating—and dying—in West Africa?

U.S. presence in the Sahel is directly related to the war on terror. American forces there are supporting a French-led military coalition that is attempting to stabilize the region and battle back against a number of militant Islamist groups.

“In West Africa, containing and degrading violent extremist organizations [VEO], such as ISIS, AQIM [al-Qaeda in the Islamic Maghreb] and Boko Haram, remains a top priority as these VEOS conduct increasingly complex and lethal attacks aimed at terrorizing civilians and destabilizing governments,” a spokesperson for U.S. Africa Command told A Beautiful Perspective via email.

According to statements given by Gen. Dunford and Secretary of Defense James Mattis, there are approximately 800 troops serving in Niger. They are supporting roughly 4,000 French troops in the area, as well as a much larger force, comprised of more than 35,000 regional soldiers.

The fall of Libyan leader Gaddafi in 2011 “started a domino effect in the larger North African and Western African region,” said Martin Quencez, an expert on French foreign policy and a fellow and senior program director of security and defense for the German Marshall Fund of the United States.

“An unknown number of fighters from the Sahelian countries were serving as part of Gaddafi’s elite force,” said Dr. Joseph Siegle, director of research at the Africa Center for Strategic Studies. “So when he was captured and killed and this group was disbanded, many of them returned to their home countries. And they brought weapons.”

Libyan arsenals, suddenly up for the taking, may have found their way into the hands of various extremist groups.

French armored vehicles heading towards the Niger border before making a left turn north in Gao, northern Mali in this image from Feb. 6, 2013. American and French forces have spent years providing training and support to the militaries of Mali, Niger and other vulnerable countries in this corner of Africa where Islamic extremism has become entrenched over the past decade. Jerome Delay/AP Photo

The Sahel became a new hub for Islamic militants. Numerous factions affiliated with al-Qaeda in the Islamic Maghreb united under the new name Jama’at Nusrat al Islam wal Muslimin (JNIM), this past April, and the ISIS-affiliated Islamic State in the Greater Sahara is active locally as well. While not generally considered part of the Sahel, Boko Haram in Nigeria has been active around the border with Niger.

In mid-2013, al-Qaeda backed Islamic militants gathered in Mali’s vast and relatively empty north began a push south to the capital of Bamako that threatened to destabilize the state and the region. France intervened on the Malian government’s behalf in a military action known as Operation Serval.

“The objective of the operation was rather minimal,” Quencez said. “It was stopping the expansion of jihadists in north Mali going down to Bamako and potentially overthrowing the government, which would create a significant new safe haven for jihadi terrorists in the Sahel.”

The United States supported French forces in Operation Serval, and has been engaged in the region ever since.

Operation Serval has given way to Operation Barkhane, a sustained effort by France, the G5 Sahel (made up of Burkina Faso, Chad, Mali, Mauritania and Niger, who work together to improve security, stability and development) and a United Nations peacekeeping force to stabilize the region. Already a massive undertaking, French forces were spread extra thin following the Paris terror attack and the redeployment of thousands of troops back home. According to Quencez, this made U.S. backing of Operation Barkhane even more crucial.

While France has a formidable army which can deploy quickly—and, crucially, the support of the G5 Sahel—they do not have as robust an intelligence gathering operation as the U.S. forces, who provide intelligence, surveillance and refueling services to French and coalition forces. Members of the Special Forces—including the Green Berets—are training local government personnel, including in Niger.

“One component of our strategy is military cooperation with our African partner militaries,” the AFRICOM spokesperson said via email. These efforts are part of an international push to stop the spread of violent extremism in the region.

And the efforts will only increase. The Pentagon plans to focus counterterrorism work on Africa, including in the Sahel, Defense Secretary Jim Mattis told members of the Senate Armed Services Committee in a late October briefing. With 800 troops already stationed in Niger; it is almost inevitable that you will be hearing more news from West Africa.

The sheer amount of stories that have come out of Niger and the lingering operational and logistical questions about October 4—did they have enough, and accurate, intelligence? Did they change their mission? Why did they wait an hour to call for help?—have led the Pentagon to commission an investigation led by AFRICOM Major General Roger Cloutier. The FBI is also investigating the ambush due to potential threats to national security.

The Pentagon expects the official report in January.