After the Arab spring of 2011 brought Islamist movements to the fore, Mr Erdogan promoted Turkey as a model of Islamist governance—and himself as leader of the Muslim world.
Turkey has been even bolder in the part of northern Syria once controlled by the main local Kurdish force, the People’s Protection Units (YPG).
Turkey says it has “neutralised” over 1,400 Kurdish fighters in Iraq and Syria this year.
Mr Erdogan feared that an alliance of Egypt, Israel, Greece and Cyprus might squeeze Turkey out of the area.
Egypt has mobilised its forces on Libya’s border and vows to cross it if Turkey advances further.