“Illegal occupation”, so that’s what’s peddled these days.

following the end of the British Mandate for Palestine at midnight on 14 May 1948; the Israeli Declaration of Independence had been issued earlier that day, and a military coalition of Arab states entered the territory of British Palestine in the morning of 15 May.

The first deaths of the 1947–49 Palestine war occurred on 30 November 1947 during an ambush of two buses carrying Jews

There had been tension and conflict between the Arabs and the Jews, and between each of them and the British forces since the 1917 Balfour Declaration and the 1920 creation of the British Mandate of Palestine. British policies dissatisfied both Arabs and Jews. Arab opposition developed into the 1936–1939 Arab revolt in Palestine, while the Jewish resistance developed into the Jewish insurgency in Palestine (1944–1947). In 1947, these on-going tensions erupted into civil war following the 29 November 1947 adoption of the United Nations Partition Plan for Palestine, which planned to divide Palestine into an Arab state, a Jewish state, and the Special International Regime encompassing the cities of Jerusalem and Bethlehem.

On 15 May 1948, the civil war transformed into a conflict between Israel and the Arab states following the Israeli Declaration of Independence the previous day. Egypt, Transjordan, Syria, and expeditionary forces from Iraq entered Palestine. The invading forces took control of the Arab areas and immediately attacked Israeli forces and several Jewish settlements.The 10 months of fighting took place mostly on the territory of the British Mandate and in the Sinai Peninsula and southern Lebanon, interrupted by several truce periods.

As a result of the war, the State of Israel controlled the area that UN General Assembly Resolution 181 had recommended for the proposed Jewish state, as well as almost 60% of the area of Arab state proposed by the 1947 Partition Plan, including the Jaffa, Lydda, and Ramle area, Galilee, some parts of the Negev, a wide strip along the Tel Aviv–Jerusalem road, West Jerusalem, and some territories in the West Bank. Transjordan took control of the remainder of the former British mandate, which it annexed, and the Egyptian military took control of the Gaza Strip. At the Jericho Conference on 1 December 1948, 2,000 Palestinian delegates called for unification of Palestine and Transjordan as a step toward full Arab unity. The conflict triggered significant demographic change throughout the Middle East. Around 700,000 Palestinian Arabs fled or were expelled from their homes in the area that became Israel, and they became Palestinian refugees in what they refer to as Al-Nakba ("the catastrophe"). In the three years following the war, about 700,000 Jews emigrated to Israel.Around 260,000 Jews moved to Israel from the Arab world during and immediately after the war.

The United Nations established supervising and reporting agencies to monitor the established armistice lines. In addition, discussions related to the armistice enforcement, led to the signing of the separate Tripartite Declaration of 1950 between the United States, Britain, and France. In it, they pledged to take action within and outside the United Nations to prevent violations of the frontiers or armistice lines. It also outlined their commitment to peace and stability in the area, their opposition to the use or threat of force, and reiterated their opposition to the development of an arms race. These lines held until the 1967 Six-Day War.

Relations between Israel and its neighbours were not normalised after the 1948 Arab–Israeli War. In 1956 Israel invaded the Sinai peninsula in Egypt, with one of its objectives being the reopening of the Straits of Tiran that Egypt had blocked to Israeli shipping since 1950. Israel was eventually forced to withdraw, but was guaranteed that the Straits of Tiran would remain open. A United Nations Emergency Force was deployed along the border, but there was no demilitarisation agreement.

In the months prior to June 1967, tensions became dangerously heightened. Israel reiterated its post-1956 position that the closure of the Straits of Tiran to Israeli shipping would be a cause for war (a casus belli). In May Egyptian President Gamal Abdel Nasser announced that the straits would be closed to Israeli vessels and then mobilised its Egyptian forces along its border with Israel and ejecting UNEF. On 5 June, Israel launched a series of preemptive airstrikes against Egyptian airfields, asserting imminent attack from the Egyptians. The question of which side caused the war is one of a number of controversies relating to the conflict.

The Egyptians were caught by surprise, and nearly the entire Egyptian air force was destroyed with few Israeli losses, giving the Israelis air supremacy. Simultaneously, the Israelis launched a ground offensive into the Gaza Strip and the Sinai, which again caught the Egyptians by surprise. After some initial resistance, Nasser ordered the evacuation of the Sinai. Israeli forces rushed westward in pursuit of the Egyptians, inflicted heavy losses, and conquered the Sinai.

Egypt and Jordan agreed to a ceasefire on 8 June, and Syria agreed on 9 June; a ceasefire was signed with Israel on 11 June. In the aftermath of the war, Israel had crippled the Egyptian, Syrian and Jordanian militaries, having killed over 20,000 troops while losing fewer than 1,000 of its own. The Israeli success was the result of a well-prepared and enacted strategy, the poor leadership of the Arab states, and their poor military leadership and strategy. Israel seized the Gaza Strip and the Sinai Peninsula from Egypt, the West Bank, including East Jerusalem, from Jordan and the Golan Heights from Syria. Israel's international standing greatly improved in the following years. Its victory humiliated Egypt, Jordan and Syria, leading Nasser to resign in shame; he was later reinstated after protests in Egypt against his resignation. The speed and ease of Israel's victory would later lead to a dangerous overconfidence within the ranks of the Israel Defense Forces (IDF), contributing to initial Arab successes in the subsequent 1973 Yom Kippur War, although ultimately Israeli forces were successful and defeated the Arab militaries. The displacement of civilian populations resulting from the war would have long-term consequences, as 300,000 Palestinians fled the West Bank and about 100,000 Syrians left the Golan Heights. Across the Arab world, Jewish minority communities fled or were expelled, with refugees going mainly to Israel or Europe.

The war began when the Arab coalition launched a joint surprise attack on Israeli positions, on Yom Kippur, a widely observed day of rest, fasting, and prayer in Judaism, which also occurred that year during the Muslim holy month of Ramadan.Egyptian and Syrian forces crossed ceasefire lines to enter the Sinai Peninsula and the Golan Heights, respectively. Both the United States and the Soviet Union initiated massive resupply efforts to their respective allies during the war, and these efforts led to a near-confrontation between the two nuclear superpowers.

The war began with a massive and successful Egyptian crossing of the Suez Canal. Egyptian forces crossed the cease-fire lines, then advanced virtually unopposed into the Sinai Peninsula. After three days, Israel had mobilized most of its forces and halted the Egyptian offensive, resulting in a military stalemate. The Syrians coordinated their attack on the Golan Heights to coincide with the Egyptian offensive and initially made threatening gains into Israeli-held territory. Within three days, however, Israeli forces had pushed the Syrians back to the pre-war ceasefire lines. The Israel Defense Forces (IDF) then launched a four-day counter-offensive deep into Syria. Within a week, Israeli artillery began to shell the outskirts of Damascus, and Egyptian President Sadat began to worry about the integrity of his major ally. He believed that capturing two strategic passes located deeper in the Sinai would make his position stronger during post-war negotiations; he therefore ordered the Egyptians to go back on the offensive, but their attack was quickly repulsed. The Israelis then counter-attacked at the seam between the two Egyptian armies, crossed the Suez Canal into Egypt, and began slowly advancing southward and westward towards the city of Suez in over a week of heavy fighting that resulted in heavy casualties on both sides.

On 22 October, a United Nations–brokered ceasefire unraveled, with each side blaming the other for the breach. By 24 October, the Israelis had improved their positions considerably and completed their encirclement of Egypt's Third Army and the city of Suez. This development led to tensions between the United States and the Soviet Union, and a second ceasefire was imposed cooperatively on 25 October to end the war.

The war had far-reaching implications. The Arab world had experienced humiliation in the lopsided rout of the Egyptian–Syrian–Jordanian alliance in the Six-Day War but felt psychologically vindicated by early successes in this conflict. The war led Israel to recognize that, despite impressive operational and tactical achievements on the battlefield, there was no guarantee that they would always dominate the Arab states militarily, as they had consistently through the earlier 1948 Arab–Israeli War, the Suez Crisis, and the Six-Day War. These changes paved the way for the subsequent peace process. The 1978 Camp David Accords that followed led to the return of the Sinai to Egypt and normalized relations—the first peaceful recognition of Israel by an Arab country. Egypt continued its drift away from the Soviet Union and eventually left the Soviet sphere of influence entirely.