Turkey could not endure any possibility of Kurdish self-determination or even basic human rights either at home or beyond Turkish borders.
Fighting has calmed since March when Ankara, which backs some groups opposed to President Bashar al-Assad, agreed a ceasefire with Moscow, which has supported Damascus with heavy air power.
The question that remains to be answered now is: Will Idlib hold?
Turkish media has pushed a narrative that the country has managed to keep the coronavirus at bay while neighboring countries are being infected.
After six hours of talks with Vladimir Putin, a somber Erdogan announced an accord which cements territorial gains by Russian-backed Syrian forces over Turkish-backed rebels.
Russia and Turkey back opposing sides in Syria's nine-year conflict, with Moscow supporting President Bashar al-Assad and Turkey backing some rebel groups.
Turkish Defense Minister Hulusi Akar responded, vowing retaliation against any attack on Turkish forces or observation posts in Idlib under Turkey's right to self-defense.
Assad's forces, supported by Russian air power, are trying to retake the last large rebel-held region after nine years of war. Nearly a million Syrians have been displaced by the latest fighting.
Turkish forces retaliated and destroyed 21 "regime targets", the ministry said, adding the soldier was a tank mechanic who died while being transferred to the hospital.