Israel led the assault on Egypt, and it was they that initiate4d the actions against the Egyptians, Howewver it was the direct actions by the Americans that led nasser to take the unilateral action that he did.
In 1956, the Suez Canal became the focus of a major world conflict. The canal represented the only direct means of travel from the Mediterranean to the Indian Ocean, making it vital to the flow of trade between Asia, the Middle East, Europe, Australasia and the U.S. Normally, free passage was granted to all who used the canal, but Britain and France desired control of it, not only for commercial shipping, but also for colonial interests. The Egyptian government had just been taken over by Gamal Abdel Nasser, who felt the canal should be under Egyptian control. The United States and Britain had promised to give aid to Egypt in the construction of the Aswan Dam in the Nile. This aid was retracted however, and in retaliation Nasser nationalized the canal. He intended to use the funds raised from the operation of the canal to pay for the Dam. This was an unnacceptable impost on free trade (though free paassage through the canal was something that has never returned dince 1956) and the eventual outcome was to have major impacts in the terms of trade between Europe and the Far East. The outcomes of the Suez crisis was to spell the end of both colonialism and paradoxically also free trade with the far east. Perhaps both went hand in hand with each other. In any event, the Suez crisis marked the closure of this vital transport link for more than 20 years. For countries like Australia and NZ, this meant our agricultural produce was no longer viable as a trade item in Europe. It marked a definite point of departure of these former colonies from their traditional markets. In the case of Australia we replaced European markets with East Asian markets, and really have not mourned that change at all, at least eventually.....
Returning to the events of 1956....angry at British and French politicians joined forces with Israel (who led the charge for security reasons mostly) , a long time enemy of Egypt, in an attack against Nasser. The Israeli army marched toward the canal on October 29, 1956. Britain and France reinforced the Israelis, and the joint effort defeated the Egyptian army quickly. Within ten days, British and French forces had completely occupied the Suez region. Egypt responded by sinking 40 ships in the canal, blocking all passage (and these wrecks remained in place for many years after the event). The United Nations sought to resolve the conflict and pressured the two European powers to back down. The rest of the world shunned Britain and France for their actions in the crisis, and soon the UN salvage team moved in to clear the canal (but what is not often reported is that the task remained incomplete) . Britain and France were forced to back down, and control of the canal was given back to Egypt in March 1957. The Egyptian government was allowed to maintain control of the canal as long as they permitted all vessels of all nations free passage through it. They circumvented this undertaking by simply leaving the wrecks they had sunk in the canal, thereby denying access to international trade. 20 years, and three wars later, and this situation still remained unresoloved.