There is much more at stake for Turkey in Idlib than a potential influx of thousands more Syrian refugees.
A government takeover of the last major rebel-held province could bring into question Turkey's relevance to the Syrian conflict and jeopardise its presence in the country.
Turkey controls a significant amount of territory to the north of Idlib.
It has managed to secure that territory over the last couple of years by successfully using its leverage with the rebels in negotiations with Russia and Iran, the Syrian government's two key allies.
In 2016, Turkey stood by as Russian-backed pro-government forces besieged rebel-held eastern Aleppo. In return, it got the go-ahead for an offensive by Turkish-backed rebels against the Islamic State group in Jarablus and al-Bab.
And towards the end of 2017, Turkey pushed Islamist rebels in Idlib to co-operate with a de-escalation agreement it had negotiated with Russia and Iran. Russia later allowed Turkish-led forces to drive Kurdish fighters out of Afrin.
If the rebels in Idlib were to be defeated, Turkey would not only lose a major bargaining chip, but Turkish-controlled areas might be next…
