Three Ottoman slights hardened Mehmed Ali toward final rupture. [causal]
And it was lost not through any negligence or misconduct on his part but because of the “obstinate and arrogant refusal of the Porte to accept European mediation” in the whole issue of Greek independence. This intransigent position on the part of the Porte did not change after Navarino: the Porte refused to hear of any requests by Ibrahim to withdraw to Egypt and instead kept on pressing on him the importance of holding on to all territories under his control as well as initiating further campaigns against the Christian population in the Morean peninsula and, if need be, to burn all villages on his way. Mehmed Ali refused to listen to these stubborn and unrealistic demands of the Porte and proceeded to sign a treaty with the European powers guaranteeing the safety of his son’s withdrawal from the Greek mainland. Moreover, and this must have been felt more heartily, the Sultan refused to give Mehmed Ali Syria as he had hoped and instead gave him the island of Crete to govern, an island he had already captured and which was in a constant state of rebellion since the start of the Greek revolution. Furthermore, its resources and importance were not to be compared to those of Syria. Never again would he accept the docile role that was expected of him and he would always be on the look-out for any pretext to take what he had been coveting for a long time: Syria.
Builds on: "Mehmed Ali's denied Syrian reward precipitated his military seizure."
Khaled Fahmy, All the Pasha_s Men_ Mehmed…, loc. 239