Peter Neumann lays out the history of Bashar al-Assad’s nurturing and manipulation of jihadists in Syria, as a consequence of which for most of 2003 the bulk of foreign fighters joining the insurgency in Iraq were Syrians.

The most significant, long-term consequence of Assad’s policy arose from the opening up of Syria to international jihadist networks. Before he turned his country into a transit point for foreign fighters, Syrian jihadists had been largely homegrown. If international links existed, they were to neighbouring countries. Al-Qaida had always had prominent Syrians as members – the strategist Abu Musab al-Suri, for example, or Abu Dahdah, who was sentenced to a lengthy prison term in Spain – but they had fled the country in the early 1980s, and there is no evidence that they directed jihadist activities inside Syria, sought to organise them, or even showed any interest in doing so. The terrorism experts were not entirely wrong, therefore, in believing that – for some time at least – Syria was outside al-Qaida’s orbit.

This changed in 2003 when Assad allowed the jihadists in his country to link up with Zarqawi and become part of a foreign fighter pipeline stretching from Lebanon to Iraq, with way points, safehouses and facilitators dotted across the country. With the active help of Assad’s intelligence services, Syria was opened to the influx – and influence – of experienced and well-connected jihadists from Libya, Saudi Arabia, Algeria, Tunisia, Yemen and Morocco, who brought with them their contact books, money and skills. Within a few years, the country ceased to be a black spot on the global jihadist map: by the late 2000s it was familiar terrain to foreign jihadists, while jihadists from Syria had become valued members of al-Qaida in Iraq, where they gained combat experience and acquired the international contacts and expertise needed to turn Syria into the next battlefront.

When the current conflict broke out, it was hardly surprising that jihadist structures first emerged in the eastern parts of the country, where the entry points into Iraq were located, and in places like Homs and Idlib, which were close to Lebanon; or that it was jihadists – not the Muslim Brothers – who could offer the most dedicated and experienced fighters with the skills, resources, discipline and organisation to hit back at the government. They were also the ones who found it easiest to prevail on international networks of wealthy sympathisers, especially in the Gulf, to supply weapons and funding. The clearest example is the Islamic State of Iraq and Greater Syria (ISIS), a viciously sectarian player in the current conflict, descended from Zarqawi’s al-Qaida in Iraq, which draws on the same networks and supply lines that enabled the transfer of fighters from Syria to Iraq – except that now, of course, the traffic flows in both directions.

Given the history and genesis of groups like ISIS, many Syrian opposition figures now claim that the jihadist groups in Syria are puppets of Assad, and that they continue to be used and manipulated by Syrian intelligence in its efforts to discredit the revolution, divide the opposition and deter the West from intervening on their behalf. Indeed, there can be little doubt that many of the older and more senior figures in groups like ISIS will have records with Syrian intelligence, and that some are likely to be collaborating with the regime. Nor is there any question that the Syrian government, which is fighting large numbers of secular defectors from its own forces, has an interest in portraying the opposition as crazy fanatics, or that some of its actions – such as releasing more Islamists from Sednaya prison, or sparing ISIS-controlled areas from attack – have been designed to strengthen the jihadists vis-à-vis their rivals. There still is no solid evidence, however, that the jihadists as a whole are controlled by the regime, despite repeated announcements by opposition figures that such evidence would be forthcoming. No one doubts that jihadist groups in Syria draw on external support and international networks, including foreign fighters from across the Middle East and even Europe. But the reason they were able to mobilise them – and mobilise them quickly – is that Assad’s government had helped to set them up.