Hypothesizing the Gulfs of Aquaba and Suez reaching the Mediterranean. The Jordan valley would be flooded by seawater and the Sinai is cut off along the line of OTL Suez Canal and from Aquaba through the Negev to Gaza.
Butterflies obviously enormous - he who owns the Sinai controls access to Egypt one way and the Fertile Crescent the other way. Egypt, Persia, Alexander, the Ptolemaic Greeks, the Romans, the Arabs, later on France, Britain...
...Enormous butterflies, starting with Genesis and the Hyksos...
Have fun.