The UK is to send 250 troops to Mali in the biggest peacekeeping deployment since Bosnia and potentially the most dangerous mission for British forces since Afghanistan.
The soldiers will form a long-range reconnaissance task group, specifically chosen for their ability to operate in small teams and in violent, contested areas of the country.
They will be asked reach parts of Mali that most militaries cannot, to feed on-the-ground intelligence back to the mission headquarters in Gao. They will arrive in the country early next year.
"They will do the part of the heavy lifting. They will do the operations in very contentious areas... where we have a great deal of uncertainty. They will do operations where we face threats to us and to the civilian populations," the UN Force Commander Lieutenant General Dennis Gyllensporre explained.
Although wearing the distinctive light blue UN helmets and deployed with a peacekeeping mandate, it's privately acknowledged that they will likely be targeted by extremist groups fighting for power in one of the world's poorest and most dangerous countries.
The British deployment comes as security in Mali and the wide Sahel region has deteriorated rapidly in recent months, causing thousands of people to be displaced and a dramatic spike in deaths.
A range of violent factions - some allied to al Qaeda - are vying for influence, and Islamic State in West Africa has successfully established a foothold in Mali.
Such is the concern within the British government that a Joint Sahel Task Group has been established in London to address the potential threats from what is known as the G5: Mali, Niger, Chad, Burkina Faso and Mauritania.
A regional hub has been set up in Dakar and two new British embassies will open in Niger and Chad. Close to £10m will be spent on security and humanitarian initiatives in the region this year.
Albeit relatively small, the deployment has been welcomed by the UN in New York and is being seen in the British government as one of the most significant military commitments since Afghanistan and the fight against Islamic State.
Defence Secretary Penny Mordaunt travelled to Mali to make the announcement in person.
She said: "In one of West Africa's poorest and most fragile regions it is right that we support some of the world's most vulnerable people and prioritise our humanitarian and security efforts in the Sahel."
France, with historical links in Mali, is the biggest military force in the country with more than 4,500 troops fighting Islamist extremists. The Paris government has paid a heavy toll for the five-year commitment, losing 15 soldiers and many more injured.
Three RAF Chinook helicopters and around 100 personnel have been operating with French forces in the north of the country since 2018, in a non-combat role. The Chinooks have provided valuable heavy-lift to the mission, a capability the French don't have.
That commitment was recently extended by a further six months to June 2020, viewed as a gesture of Anglo-French goodwill post-Brexit.