The five-nation mission began operations in 2017, showcased as an unprecedented example of cooperation in one of the world's troubled regions.
But the force -- originally gathering Burkina Faso, Chad, Mali, Mauritania and Niger -- has achieved meagre results and the Sahel's security crisis continues to deepen.
Added to this have been two hammer blows, delivered in quick succession this year.
In April, 1,200 Chadian soldiers based in Niger left in secret for N'Djamena, according to G5 and French military officials.
The following month, Mali announced it would leave the group over a dispute with France, forcing all the force's commanders to abandon their base in Bamako and relocate to the Chadian capital N'Djamena.
"They left overnight, leaving everything behind, even the cars," a G5 official told AFP.
"The G5 is dead," Niger's president, Mohamed Bazoum, told the French newspaper La Croix in May.
But last week, he and President Mahamat Idriss Deby of Chad sounded a different tone, announcing an upcoming meeting between the force's four remaining members to "ensure that the G5 is viable."
"We have not yet considered that it is over for the G5 Sahel -- we will fight," Bazoum said. "Let's remain optimistic."
An immense task
The regional grouping began with an ambitious idea to create a joint military force that would go hand in hand with development projects.
The force was largely financed by the European Union (EU) and its operations were supported by France.
It represented, in the eyes of international partners, a solution in a region plagued by jihadist violence.
Its eight battalions comprised about 5,000 troops, based in their own countries, with the exception of a Chadian battalion deployed in Niger. They were tasked with coordinating operations in the hotspot border areas.
There are numerous reasons for its decline, two G5 officials told AFP.
These include chronic underfunding, disparate political will among member countries and regional politics.
Mali has undergone two coups in two years, and there have been military takeovers in Burkina Faso and Chad.
In 2021, Chad was meant to hand the G5 presidency over to Mali but did not -- a move that Bamako interpreted as French interference.
Paris is reputedly close with N'Djamena, and Mali's ruling junta, led by Colonel Assimi Goita, lashed the G5's "instrumentalisation" before slamming the door.
"It would be hard not to see the French hand behind this refusal to transfer the presidency," said Malian researcher Boubacar Haidara.
The G5 Sahel "has been perceived since the beginning as being controlled by Paris," said Ornella Moderan, from the South Africa-based Institute for Security Studies (ISS).
But, she said, it has above all "suffered from variable political support from one member state to another."
Since the creation of the G5, "there have been no joint operations between Burkina and Mali, let alone between Niger and Mali," Niger's foreign minister, Hassoumi Massoudou, said last week.
A 'necessary tool'
In Burkina Faso, people are questioning "the survival of the G5," according to a source close to the authorities, although no departure is in sight.
Despite the force's travails, Burkinabe troops in the G5 have continued to operate with the Nigeriens in recent months.
"There is no other option than to work together," said a member of the joint force.
"Can the G5-Sahel pull through?" asked Mahamat Saleh Annadif, a senior UN official.
"I can't say, but in any case, by design, it remains a necessary tool."
But how can the remaining four states be convinced to stay without the participation of Mali, whose territory is the epicentre of the conflict?
"Being a member of the G5 brings money and logistical support from partners -- the states know that," said an African diplomat in Bamako.
The diplomat said the UN provides G5 contingents with fuel and food -- things that are always needed for troops, whether or not they are wearing the G5 badge.
For Massoudou, the G5 Sahel's future lies with Bamako.
"When Mali has democratically elected authorities who normalise relations with its neighbours, we could revive this organisation," he said.
Mali's military junta has bust up with France and its relationship with the UN peacekeeping mission is also suffering friction.
And it has only just turned the page on a political tussle with the regional bloc ECOWAS over its return to civil rule. Delayed elections are now scheduled for February 2024.