The Syrian rebels' advance has been surprising. In a matter of days, they took almost the entire provinces of Idlib and Aleppo, and were at the gates of Hama, a town on the road to Damascus.
But perhaps even more surprising is the fact that they seem to have moulted from an international terrorist movement to a conservative local group.
When I visited the Syrian rebel front several times in 2012 and 2013, I saw radicalisation increasing, and the secular Free Syrian Army being infiltrated by fundamentalists.
The leader of the so-called Islamic State or IS in Iraq, Abu Bakr al-Baghdadi had just sent his friend Abu Muhammad al-Jolani to Syria to establish Jabhat al-Nusra, a branch of IS.
However, when the caliphate was declared in the summer of 2014, Jolani refused to let his militia merge into IS and swore allegiance to al-Qaeda instead. To the outside world, this made little difference. Jabhat al-Nusra was rightly considered a terroristic jihadist militia with the West as its main enemy.
Syria observers had noticed that Jabhat al-Nusra had changed its name and cut its links with al-Qaeda in 2016 and did so again in 2017, becoming Hayat Tahrir ash-Sham (HTS) or the Organisation for the Liberation of the Levant.
However, the leaders remained the same, making it look like a sham to most pundits.
When rebels were rapidly capturing Aleppo last week, it appeared that the leadership of that operation was being taken up by HTS. That made commentators and Syrian activists alike nervous. Is this now the great liberation from president Bashar al-Assad's reign of terror?
However, videos of the march posted on social media showed a different picture.
There are no black flags to be seen, no Afghan attire, nor horror images of Christians or other minorities being slaughtered. The images that do show this, after thorough investigation, appear to be systematically older images, remarkably often from Iraq, which are now being redistributed as propaganda.
Last year, France24 journalist Wassim Nasr asked himself the same question after noticing that the discourse of al-Jolani, the leader of HTS, had become more moderate. Was this an adjustment in communication or has something more to the point actually changed? He went to Syria to find out for himself.
What Nasr immediately noticed was that no armed militants could be seen on the streets. Moreover, there were no jihadi black flags to be seen.
Instead, the flag of the Syrian opposition (with three stars, instead of the two stars in the Syrian flag) was hanging. Everything seemed to indicate civilian rule.
Moreover, women and men could study together at schools and universities. A second observation was that minorities, from Christians to Shiites, were free to practice their religion. Churches destroyed in bombings were rebuilt. The only thing the churches were not allowed to do was ring their bells.
The journalist visited several villages and towns to make sure he did not see only what the HTS rebels wanted him to see. After the hypertribalisation of IS, a process of detribalisation now seems to be taking place.
During his conversation with HTS leaders, including Jolani himself, he kept getting the same message. They had become convinced that IS and al-Qaeda were no longer a model for them.
More so, they felt that this terrorist and anti-Western ideology of international jihad was wrong because it had brought about "only the destruction and failure of local communities". According to the ideological leader of HTS, they were therefore doing everything possible to ensure that their members would not join IS or al-Qaeda.
Finally, these leaders indicated that for them the West was no longer an enemy, and that they even hoped for the support of Europe and the US in their fight against Assad and the forces supporting him, especially Iran, Russia and Hezbollah.
Again, HTS militants have not suddenly become secular, democratic pacifists, but neither can we deny that a kind of deradicalisation has taken place.
After 13 years of war in Syria, and many defeats by the opposition, there has apparently been a realisation that things have to change.
Moreover, some experts indicate that Turkey would not support this operation if it were led by sectarian jihadists.
It brings us to the question: why is Turkey supporting this operation? I see three reasons.
First, Assad is no friend of the Turks. For several years now, Syria has become a narco-state that is disrupting the entire region with the sale of captagon. It somewhat resembles the 19th-century opium strategy of the British against China. Everyone wants this to stop.
Second, much of north-east Syria is currently occupied by Kurdish militias linked to the PKK, a thorn in Turkey's side. The current operation is clearly also targeting these militias.
Finally, Turkey has some 4.5 million Syrian refugees. As long as Assad is in power, they cannot return.
Moreover, the moment was perfect. The three forces supporting Assad now have other priorities.
Russia has a war in Ukraine while Hezbollah has just emerged weakened from a war with Israel. Iran is busy on many fronts and may also have been surprised by the well-prepared Syrian rebels.
The question is how should we as Europe respond to this now?
Do we once again go along with the Assad narrative that we have to choose between him and international jihad?
Or do we give the rebels the benefit of the doubt to get rid of one of the world's worst dictatorships?
It remains an unclear story for now. But it would be a mistake to continue to see everything from a purely ideological lens, based on 9/11 and other attacks in Europe, and forget what is happening and changing on the ground.
Koert Debeuf is professor of Middle East at the Vrije Universiteit Brussels (VUB), and chair of the board of EUobserver.
Koert Debeuf is professor of Middle East at the Vrije Universiteit Brussels (VUB), and chair of the board of EUobserver.