To prevent another week of terror, our state must not become a vast Isis recruiting sergeant

British Libyans and Libyan exiles who had their passports returned to fight Gaddafi were always unlikely to return as model citizens

National Transitional Council fighters take part in a street battle in Sirte, Libya in the final assault on Gaddafi's hometown in 2011 (Getty)

The massacre in Manchester is a horrific event born out of the violence raging in a vast area stretching from Pakistan to Nigeria and Syria to South Sudan. Britain is on the outer periphery of this cauldron of war, but it would be surprising if we were not hit by sparks thrown up by these savage conflicts. They have been going on so long that they are scarcely reported, and the rest of the world behaves as if perpetual warfare was the natural state of Libya, Somalia, Syria, Iraq, Yemen, South Sudan, North-east Nigeria and Afghanistan.

It is inevitable that, in the wake of the slaughter in Manchester, popular attention in Britain should be focussed on the circumstances of the mass killing and on what can be done to stop it happening again. But explanations for what happened and plans to detect and neutralise a very small number of Salafi-jihadi fanatics in UK, will always lack realism unless they are devised and implemented with a broad understanding of the context in which they occur.

It is necessary at this point to emphasise once again that explanation is not justification. It is, on the contrary, an acknowledgement that no battle – certainly not a battle to defeat al-Qaeda and Isis – can be fought and won without knowing the political, religious and military ingredients that come together to produce Salman Abedi and the shadowy Salafi-jihadi network around him.

The anarchic violence in the Middle East and North Africa is underreported and often never mentioned at all in the Western media. Butchery of civilians in Baghdad and Mogadishu has come to seem as normal and inevitable as hurricanes in the Caribbean or avalanches in the Himalayas. Over the last week, for instance, an attack by one of the militias in the Libyan capital Tripoli killed at least 28 people and wounded 130. The number is more than died in Manchester, but there were very few accounts of it. The Libyan warlords, who pay their fighters from the country’s diminished oil revenues, are thoroughly criminalised and heavily engaged in racket from kidnapping to sending sub-Saharan migrants to sea in sinking boats. But their activities are commonly ignored, as if they were operating on a separate planet.

Britain played a central role in overthrowing Muammar Gaddafi in 2011 without considering that there was nothing but such warlords remaining to replace his regime. I was in Benghazi and Tripoli at that time and could see that the rebel bands, financed by Gulf oil states and victorious only because of Nato airstrikes, would be incapable of filling the vacuum. It was also clear from an early stage that among those taking advantage of this void would be al-Qaeda and its clones.

But it is only since last Monday that people in Britain have come to realise that what happened in Libya in 2011 dramatically affects life in Britain today.

British Libyans and Libyan exiles in Britain, who saw their “control orders” lifted and their passports returned by MI5 six years ago so they could go and fight Gaddafi were never going to turn into sober citizens the day after his fall. Just as the link is undeniable between the perpetrators of 9/11 and the US and Saudi backing for Jihadis fighting the Communists in Afghanistan in the 1980s, so too is the connection between the Manchester bombing and the British Government using Salafi-jihadis from the UK to get rid of Gaddafi.

The British Government pretends that anybody making this obvious point is seeking to limit the responsibility of the killers of 9/11 and the Manchester attack. The Conservative response to Jeremy Corbyn’s common sense statement that there is an obvious link between a British foreign policy that has sought regime change in Iraq, Syria and Libya and the empowerment of al-Qaeda and Isis in these places has been dismissive and demagogic. The venom and hysteria with which Mr Corbyn is accused of letting the bombers morally off the hook has much to do with the General Election, but may also suggest a well-concealed suspicion that what he says is true.

The Manchester bombing is part of the legacy of failed British military interventions abroad, but is this history useful in preventing such calamities as Manchester happening again? Analysis of these past mistakes is important to explain that terrorists cannot be fought and defeated while they have safe havens in countries that have no governments or central authority. Everything should be done to fill these vacuums, which means that effective counter-terrorism requires a sane foreign policy devoted to that end.

There should be nothing mysterious about the cause and effect which led to the Manchester bombing. Yet the same mistakes have been made by Britain in Iraq in 2003, Afghanistan in 2006, Libya in 2011 and in Syria over the same period.

It is no advertisement for President Bashar al-Assad to say that any well-informed assessment of the balance of forces in Syria from 2012 onwards – and the powerful foreign allies supporting each side – showed that Assad was likely to stay in power. Fuelling the war with the expectation that he would go was unrealistic and much to the advantage of al-Qaeda, Isis and those who might target Britain.

Eliminating the bombers' safe havens is a necessity if the threat of further attacks is to be lifted. Security measures within Britain are never going to be enough because the al-Qaeda or Isis targets are the entire British population. They cannot all be protected, particularly as the means of murdering them may be car or a kitchen knife. In this sense, the bomber will always get through, though it can be made more difficult for him or her to do so.

Better news is that the number of Salafi-jihadi networks is probably pretty small, though Isis and al-Qaeda will want to give the impression that their tentacles are everywhere. The purpose of terrorism is, after all, to create pervasive fear. Experience in Europe over the last three years suggests that the number of cells are limited but that committed Jihadis can be sent from Libya, Iraq or Syria to energise and organise local sympathisers to commit outrages.

Another purpose of terrorism is to provoke an overreaction, in this case the communal persecution or punishment of all Muslims in Britain. The trap here is that the state becomes the recruiting sergeant for the very organisations it is trying to suppress, The ‘Prevent’ programme may be doing just this. Such an approach is also counter-effective because so many people are regarded as suspicious that there are too little resources to focus on the far smaller number who are really dangerous.

Atrocities such as Manchester will inevitably lead to friction between Muslims and non-Muslims and, if there are more attacks, sectarian and ethnic antipathies will increase. Downplaying the religious motivation and saying the killers “have nothing to do with real Islam” may have benign intentions, but has the disadvantage of being glaringly untrue. All the killers have been Muslim religious fanatics.

It might be more useful to say that their vicious beliefs have their roots in Wahhabism, a very small portion of the Muslim world population living in Saudi Arabia. Of course, this would have the disadvantage of annoying Saudi Arabia, whose rulers Britain and much of the rest of the world are so keen to cultivate.