They also have everything to lose if there is no agreement. Hamas would lose an opportunity to gain some respect in the international community, which it would exploit to undermine Abbas and crawl its way back into a position where it can attack Israel.
Egypt would lose its position of power and face the unwanted presence of European and American officials forcing themselves on the scene and taking charge of negotiations and even supervision of borders.
Israel would end up with having made concessions that would be the basis for further surrenders in the next round of negotiations
No one really know what pressures Netanyahu is facing from the Obama administration, but it is a fair presumption that Washington is buying off the Prime Minister with promises to make sure the Palestinian Authority does not go to the International Criminal Court with claims of war crimes against Israel.
If an agreement is not signed tonight, a cease-fire might continue on a de facto basis.
If a truce is signed, it will give U.S. Secretary of State John Kerry an opportunity to make things worse and try again to help Abbas create the Hamas-Fatah Palestinian Authority as a country.
Whether there is or is not an agreement, everyone has a rough ride ahead.