Scholars usually agree that the Israeli decision to attack Egypt in October 1956 was motivated by fear of an impending attack by the Egyptian army. That fear was spurred by the news of a large arms deal concluded between Egypt and Czechoslovakia in September 1955. However, Czechoslovak and Soviet reports, used here for the first time, reveal that the Egyptian army was encountering serious difficulties while trying to absorb these weapons. Newly declassified military intelligence assessments reveal that Israeli analysts maintained, even after the Czech-Egyptian arms deal, that the Egyptian army was no match to the IDF. The article goes on to explore the strategic consideration that stood behind the Israeli decision to go to war.