Arriving in Benghazi by C-130 military transport plane in May 2011 as the UK special envoy’s stabilisation adviser, I could never have imagined the dark future that lay ahead. We were led to believe by political emigres in the UK that rebuilding Libya would be a relatively simple operation: Muammar Gaddafi was finished, Libya’s army was useless and its tribes were broken. A new state was to be built on fresh and firm foundations. How mistaken we were.

Just four years later, Libya is witnessing an explosion in violence, led by al-Qaida and Islamic State (Isis): the gruesome murder of Egyptian Christians, devastating suicide bombings, the kidnapping of western oil workers and the discovery of countless headless soldiers and civil-society activists in Benghazi.

One year on: chaotic Libya reveals the perils of humanitarian intervention | Peter Beaumont Read more

Back in 2011, while everyone trumpeted democracy, human rights and transparent institutions, competing Libyan political alliances differed over the means. The popular, politically liberal – though still socially conservative – majority, represented by the National Forces Alliance, promoted reform. The much less popular, but better organised, Islamists and their allies preferred continuous revolution. Unhappy with just a share in the state, the Islamists wanted to own it entirely – and now, following three consecutive losses at the ballot box, they are the ones responsible for leading Libya towards annihilation.

In retrospect, little thought was spared in London for our common values or interests when we “exited stage left” following Gaddafi’s demise in 2011. Without a long-term strategy for Libya and clear support for those who shared our values and interests (both security and commercial), we all inherited the worst of both worlds. An alarming terror threat is now metastasising beneath the “soft underbelly” of Europe. Libya’s economy – critical for the provision of jobs for the young and a barrier of prosperity against illegal migration to Europe – is at increasing risk of total collapse.

Amid the fighting on the ground, the cloud of social media “designed to influence”, and the rebadging into Isis of long-established black-flag wavers who took part in the original ousting of Gaddafi, the political challenge is clear. Poignantly, western advisers with experience of other conflict zones noted in private in 2011 that, were these extremists only a few degrees further to the east on the map – in Afghanistan for example – we would have targeted them, as opposed to coordinating with them.

Despite the remark by Philip Hammond, the British foreign secretary, that “there is no authority in Libya to engage with”, the Libyan parliament remains resolute in tribally secure Tobruk. The army and police, with whom we share security and commercial interests, are (albeit only just) containing the extremists in Benghazi. And the administration, backed by the Muslim Brotherhood, occupying Tripoli – with whom we have nothing in common – has been called out on its covert relationships with extremists.

The bottom line is: we can’t do business with the militias occupying Tripoli

Libya is not that complicated. The relationships between, and agendas of, the various and competing tribes and Islamist groupings are now well-mapped. However, what is not clear is the bureaucracy surrounding the western policy-making process. Having now returned to the commercial sector following service in Libya, I know what the bottom line is: we can’t do business with the militias occupying Tripoli. And, following the assassination of so many old friends and acquaintances from those early days and now, with the recent killing in militia-held Tripoli of Intisar al-Hasiri, another leading female civil-society activist, it is clear that only Libyans can solve their problems. However, the UK government’s fence-sitting is not only undermining the democratically elected parliament’s efforts to deal with the situation, but also endangers the UK’s long-term interests across the rest of the region.

The Libyans deserve more, and are the only ones capable of dealing with Isis – or would be if only they were empowered to do so. Without immediate and concerted intervention in support of the democratic authorities – excluding “boots on the ground”, but including the deployment of diplomatic missions to sit alongside parliament, the provision of advisers and intelligence to support the police and army’s efforts to combat Isis, and the unambiguous recognition of parliament’s supreme authority over Libya’s central bank and sovereign wealth fund – Libya risks a permanent “failed state” status.

Britain’s prime minister has a duty to urgently review the UK’s equivocal position on Libya and avoid the damaging assertion, to which civil servants cling tight, that “there is no military solution to Libya, only political”. For anyone who has read Clausewitz, military means are, of course, political. And the Islamists, including Isis, are giving us a masterclass in them.