As I understand the events were as follows 1. Tehran was concerned about a pre Obama strike on its nuclear facilities by Israel or US so told Hamas to not renew the 6 month cease fire it had used to smuggle arms to it and increase its rocket fire to 80 a day including the long range rockets it had given it. It is also why it instructed Hamas through its Damascus branch to keep fighting until the end. Hamas in Gaza was interested in the Egyptian ceasefire fire as opposed to being wiped out. 2. Egypt was scared of Hamas as a base for the Egyptian Muslim brotherhood (fanatical Islamist) who are threatening to overthrow the Egyptian government. Since Tehran is now allied to the fanatical Islamist groups this would give Tehran sway over Egypt - in particular a military foothold like it has in Lebanon where it has some revolutionary guards and controls Hezbullah. Tehran already has the Sinai Bedoin tribes on its payrole and controls the Sinai - which allowed it to send big arms to Hamas - like long range rockets that are too big for tunnels and need to be trucked in.
That is why Egypt collaborated with the Israeli military action in Gaza. Egypt also spearheaded a ceasefire proposal that was intended to facilitate the stepwise diminishing of Hamas and the reinstatement of the PA in Gaza.
