The reason why the Arab nations were hostile to Israel, and why they amassed troops near the disputed border with Israel was due to a speech made to the Knesset by David Ben-Gurion where he declared that, (due to Egypts loss of the Suez Conflict), that the 1949 Armistace with Egypt no longer existed. The following day Israel moved troops closer to Egyptian Border.
In the fall of 1948, the UN Security Council called on Israel and the Arab states to negotiate armistice agreements. Egypt aquessed, but only after Israel had routed the Egyptian army and pushed them to El Arish in the Sinai.
During this time, the British were ready to defend Egypt under an Anglo-Egyptian treaty. But, rather than accept the humiliation of British assistance, the Egyptians decided to met the Israelis at Rhodes.
United Nations mediator Ralph Bunche brought both sides together at the conference table. He warned that any delegation that walked out of the negotiations would be blamed for their breakdown.
By the summer of 1949, armistice agreements had been negotiated between Israel and Egypt, Jordan, Lebanon and Syria. Iraq, which had also fought against Israel, refused to follow suit. Bunche succeeded at Rhodes because he insisted on direct bilateral talks between Israel and each Arab state.
Meanwhile, on December 11, 1948, the General Assembly adopted a resolution calling on the parties to negotiate peace and creating a Palestine Conciliation Commission (PCC), which consisted of the United States, France and Turkey. All Arab delegations voted against it.
After 1949, the Arabs insisted that Israel accept the borders in the 1947 partition resolution and repatriate the Palestinian refugees before they would negotiate an end to the war they had initiated. This was a novel approach that they would use after subsequent defeats: the doctrine of the limited-liability war. Under this theory, an aggressor may reject a compromise settlement and gamble on war to win everything in the comfortable knowledge that, even if he fails, he may insist on reinstating the status quo ante.
Egypt had maintained its state of belligerency with Israel after the armistice agreement was signed. The first manifestation of this was the closing of the Suez Canal to Israeli shipping. On August 9, 1949, the UN Mixed Armistice Commission upheld Israel's complaint that Egypt was illegally blocking the canal. UN negotiator Ralph Bunche declared: "There should be free movement for legitimate shipping and no vestiges of the wartime blockade should be allowed to remain, as they are inconsistent with both the letter and the spirit of the armistice agreements."
On September 1, 1951, the Security Council ordered Egypt to open the Canal to Israeli shipping. Egypt refused to comply.
The Egyptian Foreign Minister, Muhammad Salah al-Din, said early in 1954:
The Arab people will not be embarrassed to declare: We shall not be satisfied except by the final obliteration of Israel from the map of the Middle East (Al-Misri, April 12, 1954).
And as you know, The Suez crisis began as a result of the increasingly independent and assertive leadership role played by Egyptian prime minister (later president) Gamal Abdel Nasser. In September 1955 Nasser arranged to purchase large amounts of Soviet weaponry from Czechoslovakia, a Communist country; at the same time, he secured promises from the U.S. and British governments to help fund a huge construction project on the Nile River, the Aswan High Dam. In effect, attempting to play both ends against the middle to achieve his own notoriety and power. After John Foster Dulles (U.S. secretary of state) took notice of Nasser's simultaneous overtures toward an Eastern-bloc nation, he successfully maneuvered to block the funding of the Aswan dam project.
Nasser responded in July 1956 by nationalizing the Suez Canal, transferring ownership of the company that controlled the daily operations of the canal from its British and French owners to the Egyptian government. He declared that he would use the company's profits of $25 million per year as an alternative source of funding for the dam. Nasser defended this action by stating that the canal was Egyptian property, and he pledged to compensate the company's shareholders and to keep the waterway open to the shipping of all nations (though Israel remained excluded under an earlier Egyptian policy).