Key principle of the 1979 agreement was that israel would engage in good faith negotiations towards a Palestinian state. 1980, Israel annexed east Jerusalem, then expanded settlement into the west bank, and 30 years later, Israel still seems to be avoiding this. I think Egypt would have fair grounds for negating this agreement, no?
Russia says air force strike 60 ISIS targets in Syria (Reuters)
from the article: Israel urges West: Make sure new Egypt regime honors peace deal