Sometimes I get angry on camera. It happened once when Finnish public television’s Paris correspondent asked me in an interview, “Aren’t you afraid of the jihadi threat? After all, there are more than a thousand French people involved in the jihad in Syria. Is this not a serious danger?”

I was too stunned to speak for a moment. Then I got annoyed.

At the time of writing, only one of these French jihadists has returned to Europe and is suspected of having committed a terrorist attack: Mehdi Nemmouche, who is accused of killing four people – including two Jews and a Muslim – in the Jewish Museum in Brussels.

I am not for a moment denying the danger such people may pose to Europe’s security – just putting it in perspective, indeed seeing it from the viewpoint of Iraqis and Syrians.

In their eyes, who are these thousand French nationals? They are criminals, thugs, a product of our society’s ills, whom we export and who vent their anger in their murderous rampages.

Take Mehdi Nemmouche, arguably the embodiment of our nightmares come true: how many people did he kill during his year in Syria? Potentially far more than the four deaths he is accused of in Brussels. Will he ever be held to account for his Syrian victims? Does anyone care about them?

Before becoming obsessed by the security risk posed by these jihadists – the products of our societies – it would be good to put aside our self-centredness and think about what crimes our fellow citizens might have committed in Syria and Iraq. Many Westerners have called for suicide attacks. And how many murders? How many acts of torture? How can we be so sensitive to our own security when we deny others the right to live in safety? Extremism feeds on this kind of double standard.

When it comes to Islamic State, Western outrage is all the easier, since the organisation records its crimes.

Media display of violence is both a form of cathartic revenge, and also a means of terrorising the enemy. Beheadings, crucifixions, summary executions are shown ad nauseam.

The political scientist François Burgat explained in an interview with RFI radio following the murder of American journalist Steven Sotloff that “Islamic State does not in my view commit more violent acts – individual or collective – than the other parties to the conflict, particularly the Syrian regime. What Islamic State does is simply integrate them into its PR policy, while the Syrian regime denies its acts of violence and places responsibility on the enemy. Islamic State uses violence as an integral part of its communication. This is the communication policy of the weak. When you’re in a dominant position, you don’t have to try to scare the enemy.”

According to the London-based Syrian Observatory for Human Rights (SOHR), Islamic State executed nearly 1500 people during the five months following the establishment of its caliphate. Among them were 900 civilians, including 700 members of the Shaytat tribe, which had opposed Islamic State, but also approximately sixty rival jihadists belonging to Jabhat al-Nusra. SOHR has also counted 500 regime soldiers who were killed, either in combat or following capture (the killing of captives is a routine war crime in Syria’s civil war).

My purpose here is not to diminish the scale of these crimes.

Quite the opposite, as a victim myself of Islamic State, I feel I have some legitimacy in condemning its violence. However, for six murdered hostages, how many Syrians and Iraqis have been tortured or killed? The scale of this violence is overwhelming. Our self-preservation instinct probably prevents us from seeing it. Yet this violence must not be ignored.

We should at least have the decency to try to understand the disgust of Syrians, who, even after more than 200,000 people have been killed, see that the West is only affected by the beheading of its hostages. These were my friends and I am bereaved. This is all the more reason for me to not to allow their deaths to be exploited for unscrupulous ends.

Quite the opposite, there needs to be a sense of proportion and a focus on the scale of these crimes. This leads to an obvious conclusion: the regime is simultaneously the instigator of the violence and its main perpetrator. The Syrian Network for Human Rights (SNHR) was founded in May 2011 to precisely document the victims of repression. The revolution was then a joyful, peaceful affair. It was imaginative and good-natured. Demonstrations had a street party atmosphere. Rebels were almost having fun, thwarting arrest by the political police. But the crackdown got tougher, and it stopped being a game.

Since the start of the revolt, SNHR has collated tens of thousands of reports of deaths, arrests, imprisonments, torture and sexual violence.

Its methodology, as set out on its website, is highly rigorous: its main limitation is not derived from the fact that cases may have been invented, but that many of them were not counted in calculations because they were not supported by sufficient evidence.

This is why Fadel Abdul-Ghany, SNHR’s president and founder, admits they have little information on regime or Islamic State losses, “because we have no sources inside these groups. By contrast, the information we have on casualties we list is very complete, with their names, age, profession all mentioned... We have remotely trained people who work for us in all of the provinces. They are in constant contact with local committees. Some of these correspondents who work for us have more than 3,000 contacts on their Skype account. But we always check information and ask for evidence, ideally photographic.”

The most credible assessments mention more than 200,000 people killed since the uprising began, but also quote a similar figure for the disappeared, political prisoners, hostages or others flung into pits. Many of these disappeared are probably already dead. It is likely that most detainees will never be seen again. In the end, it is probably reasonable to estimate that the Syrian conflict’s total number of casualties will be at least double what has already been acknowledged.

SNHR has only been able to list the names of 5,600 people killed under torture, while “Caesar’s” photographs show the bodies of 11,000 different people, murdered in just two detention centres in Damascus. In most cases, however, names are lacking. Or victims have not been recognised by relatives and are still counted among the disappeared.

In late September 2014, the network published a report on the conflict’s total number of confirmed victims: Fadel Abdul-Ghany said that his network had “discovered that the regime has killed 150 times more civilians than Islamic State”. 125,000 casualties caused by the regime, against fewer than 850 caused by Islamic State.

This disparity should come with three important qualifications: first, the regime has been killing people since the revolution began, while Islamic State appeared on the stage only in April 2013. Second, SNHR has better access to regime victims than to those of the jihadists. Third, this is a tally of civilian casualties only; it is likely that Islamic State kills a higher proportion of soldiers, while the regime concentrates on the repression of civilians.

But even if these three caveats alter the proportions, they do not contradict this conclusion: the Syrian security forces are by far the main killers and remain the fundamental threat to the Syrian people.

This is how Syrians feel, and no political solution can be found unless it addresses this fear and their need for protection.

“People have a right to be protected and live in security,” human rights activist Fadel Abdul-Ghany told me. “No one is protecting them, and the war and killings go on.” He pointed out the incoherence of Western rhetoric about protecting civilians which only attacks Islamic State and continues to ignore the regime’s crimes.

“Focusing on Islamic State means turning your back on your responsibilities, but also the implementation of reforms and real measures. The regime has committed ethnic cleansing. If such violence occurred in any country, France for instance, and the world looked on and condemned without doing anything, of course part of the French population would become extremist and begin committing crimes in turn. I fear the emergence of groups even more extreme than Islamic State.”

The regime is well aware how obsessed we are with jihadists and knows exactly how to play on it. Is it accidental that every bloodbath organised by Islamic State is followed by redoubled violence by the army? The bombing of Aleppo’s suburbs is never so severe as on the days when the videos of Islamic State hostages being decapitated are released.

While the world was looking at the face of Peter Kassig, an aid worker who had converted to Islam and whose big mistake was being too trusting, a mass grave was discovered near Homs containing the corpses of 381 men, women and children from the Baba Amr neighbourhood – people executed by regime militias. But who talked about them? Media attention will be focused elsewhere as long as we are obsessed with the jihadist threat. And the regime will go on gassing, maiming, killing and torturing.

Excerpted with permission from Jihad Academy: The Rise of Islamic State, Nicolas Hénin, translated from the French by Martin Makinson, Bloomsbury.