Conflict could send ripple effects across the southern Mediterranean region.
When the foreign powers fuelling the civil war in Libya gathered in Berlin last week and committed to refrain from interference in the conflict, there was a moment of cautious optimism.
In the end, as with so many previous initiatives intended to end violence in the north African state, the fighting resumed almost as soon as the ink had dried on the communique calling for a halt to the hostilities.
The renewed clashes have dashed hopes of a ceasefire and exposed the hypocrisy of foreign states meddling in the country, which cynically promise one thing while doing the opposite.
The UN has said “several” countries that participated in the Berlin conference have shipped foreign fighters, advanced weapons and armoured vehicles to the Libyan parties in the 10 days since the meeting.
It did not name the states, but the United Arab Emirates and Egypt have long violated an arms embargo as the main backers of General Khalifa Haftar.
The military strongman, who triggered the latest crisis by launching an offensive on Tripoli in April, also has hundreds of Russian mercenaries from the Wagner private security group on his side.
France provides political support to Gen Haftar, if not more. On the other side, Turkey has overtly armed the besieged UN-backed government of Prime Minister Fayez al-Sarraj.
Ankara last month announced it was deploying troops to support the Tripoli-based administration and has dispatched Syrian militias to Libya’s battlefields.
The Berlin conference was hastily arranged to prevent an escalation, as the beefed-up Turkish intervention and US and European concerns about Russian influence in Libya appeared to galvanise western powers to act.
Days earlier, Moscow and Ankara had sought to broker a ceasefire between the Libyan rivals in the Russian capital.
Gen Haftar never signed up to the truce.
Even as he was making his way to the Berlin conference, he thumbed his nose at the diplomatic process by ordering his loyalists to blockade Libya’s key oil terminals.
There was barely a murmur from the international community.
To be sure, Gen Haftar is a ruthless and stubborn figure, who is convinced he can seize power through the gun when few others believe a military victory is possible.
But it is unlikely that he would have been emboldened to take the steps he has without the unrelenting backing of his patrons.
Turkey’s increasing military support for the UN-backed government will also strengthen Tripoli’s belief that there is no need to enter talks on weak terms.
The result is likely to be a doubling-down by all sides in what has morphed into a multi-faceted proxy war.
Chaos in Libya since a Nato-led intervention helped topple the dictator in 2011 had already created fertile terrain for al-Qaeda and Isis, as well as for brutal smugglers exploiting migrants desperate to enter Europe.
Now there is the risk of an ever more dangerous regional conflict on the southern Mediterranean that would reverberate far beyond Libya’s borders.
The world should be deeply worried. Yet the international response has been feeble.
The UN Security Council has met 14 times on Libya since Gen Haftar launched his April offensive but has failed to produce a ceasefire resolution.
Important western allies are repeatedly violating the arms embargo with impunity.
Ultimately, it will be up to the rival Libyan factions to act in the interests of their long-suffering population. But as long as foreign powers stoke the flames, the outside world will also be culpable for the carnage.