Last month the UN Security Council approved the appointment of German diplomat Martin Kobler as special envoy for Libya. His task is to mediate a political settlement between Libya’s two rival governments and their militias. It's a mission that has received little publicity but is crucial to the efforts of the US led coalition to degrade and, ultimately, destroy ISIS.

Libya has long served as a source of foreign fighters for Syria; roughly 600 Libyans are there fighting now. As Libyan jihadists began to return from Syria in early 2014 they formed the Islamic Youth Shura Council in the northeastern town of Derna. The group declared allegiance to ISIS in late 2014 as the Cyrenaica province (Wilayat Barqa) of ISIS.

In early 2015, ISIS dramatically announced its presence in Sirte, on Libya's central coast, when it paraded a convoy of vehicles through the town. It's estimated about 2000 ISIS fighters control over 150 miles of coastline near the town.

Western officials believe the Islamic State in Libya is the only one of 10 affiliates operating under direct control of the central ISIS hierarchy. It is, however, the one they are most concerned about. Territorial control in Libya could provide ISIS with the strategic financial depth and operational reach that it needs while under siege in Syria and Iraq.

There are increasing reports that ISIS is significantly profiting from the trans-Saharan criminal economies, in particular by taxing or facilitating shipments of refugees. The group has also targeted a number of major oil fields and terminals east of Sirte. Its control of the Mediterranean coastline allows it to move foreign fighters into and out of Europe.

In the wake of the Paris attacks, much light has been shed on the group of Belgiam jihadists who carried out the attacks. They had allegedly joined a notorious Libyan fighting unit in Syria called Katibat al-Battar al-Libi (KBL), made up of Libyan nationals. The suspected mastermind of the Paris attacks, Abdelhamid Abaaoud, reportedly headed KBL.

While some importance has been attached to this alleged link between Benghazi and Paris, KBL membership by the Paris attackers does not mean the attack originated from Libyan soil, or that Libyan KBL members were involved. What the attack and the alleged Libyan link do demonstrate, however, is how Libyan jihadist experience is used by other foreign fighters — in this case Belgian — to acquire skills they can apply back home.

This is nothing new. Just as the Soviet war in Afghanistan in the 1980s spawned a generation of jihadists, many future attacks will now likely emanate or have a connection back to Syria.

What is new, as Adam Shatz thoughtfully observes in this article in the London Review of Books, is that ISIS

has managed to insert itself (…) into the two most intractable conflicts of our time: the relationship of European societies to their internal, Muslim ‘others’ and the sectarian power struggles that have engulfed the lands of Iraq and Syria since 2003. In an earlier era, these conflicts might have remained separate, but they are now linked thanks to the very devices that are the symbol of globalisation, our phones and laptops.

With this in mind, the rise of ISIS in Libya should be given greater priority by the international community. Stopping its spread will certainly not be an easy task. The jihadist field in Libya remains highly fragmented and localised, and the threats emanating from it are firmly embedded in the conflict between Libya’s two main political-military coalitions. This makes the terrorist threat in Libya bewildering and unpredictable and a military intervention ill advised.

Instead, the international community should throw its weight behind the UN sponsored talks and facilitate a political settlement to the conflict. This could pave the way for cooperation between more pragmatic military factions against ISIS and counter its growth. 

Kobler has indicated he will try and convince hardliners in both camps to accept the final draft of the UN-brokered plan rather than opening the negotiations again. However a political settlement is by no means guaranteed and it is also questionable if, once agreed, a deal would be achievable and sustainable.

In the event a deal falls through, Westerns capitals are considering targeted counter-terrorism operations against ISIS. Last month the US launched an airstrike against ISIS in Libya, its first against the group outside of Syria and Iraq. The biggest challenge it faces is isolating the terrorist threat so it can be tackled while avoiding any exacerbation of the civil war.

Regardless of the trajectory of the civil war, there are certainly structural constraints to ISIS expansion that make Libya a very different proposition to Syria. But while ISIS may not succeed in Libya in the absence of a political settlement, it certainly won't be defeated without one.