The deaths of four special forces soldiers in a small corner of Niger known as Tongo Tongo was the largest loss of American military life in Africa since the “Black Hawk Down” killings in Somalia 25 years ago.
Now an investigation into their killing last October, has found “individual, organisational and institutional failures and deficiencies” contributed to their deaths.
In America, the first response to the attack was to ask what US troops were doing in this lesser-known part of Africa, and if it was a supporting mission, why were they in danger?
The issue was inflated when one of the widows claimed President Donald Trump’s call of condolence was insensitive.
And when various explanations of how they were killed didn’t seem to add up, there were calls for an inquiry.
The investigation by the US defence department runs to thousands of pages and involved interviews with 143 witnesses. But it may still fall short in the eyes of relatives, as much of the findings remain classified.
Although identifying problems the eight-page executive summary found that “no single failure or deficiency was the sole reason” for what happened.
It said the four soldiers, Sergeant First Class Jeremiah Johnson, Staff Sergeant Bryan Black, Staff Sergeant Dustin Wright and Sergeant LaDavid Johnson, “died with honour while actively engaging the enemy”.
There had been reports that one of the men had been captured, but the Department of Defense said all died almost immediately from their injuries.
Their mission had begun on 3 October 2017 when the US special operations forces team from Camp Ouallam joined Nigerien troops in the search for a senior member of the extremist group Islamic State in the Greater Sahara (IS-GS).
But the American troops had not trained together before arriving in Niger, and, according to the defence department’s investigation, they had not rehearsed for an operation which had not been approved at a senior level.
Eventually information that IS-GS leader Doundoun Cheffou may have been located was passed up the chain of command, and an airborne raid with another team was planned.
But bad weather scuppered the mission.
Although unprepared, the soldiers known as “Team Ouallam” went ahead with the mission anyway.
They launched an early morning raid but their target had gone.
The convoy was heading back to base and stopped at the village of Tongo Tongo so Nigerien troops could get water.
After delays meeting the elders they left just before noon and were ambushed a few hundred metres from the edge of the village.
The jihadists responsible for the ambush released helmet camera footage from one of the dead soldiers and the New York Times pieced together what happened from the video.
The defence department created an animation with its interpretation of events.
The key finding was that the troops were “significantly outnumbered by a well-trained force”.
They didn’t have armoured vehicles, and were attacked by dozens of militants with motorbikes and heavy weapons.
Despite first fighting back and then attempting to retreat, four Americans and five Nigeriens were shot dead.
Although it’s just a basic graphic depicting cars as rectangles and troops as small circles, the animation shows a poignant moment.
A circle representing Staff Sergeant Wright is shown moving away from the advancing militants.
But then he stopped, turned around to help his injured colleague, and opened fire before both men were killed.
“Individual members of the team performed numerous acts of bravery while under fire,” the report said, “and their actions should be reviewed for appropriate recognition”.
Other troops were badly injured. The whole unit had taken up a “last stand” position when French fighter jets flew low overhead scattering the militants.
French helicopters then rescued the survivors.
“French and Nigerien partner forces saved American lives,” the report states, while listing some of the recommendations and actions to be taken to prevent something like this happening again.
There are around 800 American boots on the ground in Niger – and nearly twice that many deployed across the Sahel – the long southern edge of the Sahara Desert.
Their commanders say much of the work is training and mentoring Nigerien troops to counter Boko Haram, al-Qaeda affiliated groups and IS-GS.
But the investigation made it clear that soldiers were also “conducting operations”.
The rise of violent extremist groups in the Sahel is leading to a militarisation of the desert.
French and American special forces are on a counter-terrorism mission while a 14,000 strong UN force in neighbouring Mali has become the most dangerous UN peacekeeping mission in the world.
Human traffickers working the migrant routes to the Mediterranean are providing cover and funding for the terror groups who pay poor, unemployed young men to fight.
A potent mix of historical ethnic tensions, population growth, climate change and absent government is allowing Islamists to recruit, radicalise and spread across the Sahara.