Israel on the eve of the 1967 Six-Day War was a country of more than 2.5 million people, of whom approximately 87 percent were Jews. Its 7,200 square miles meant it roughly equaled in size the state of New Jersey on the U.S. East Coast. That is, it comprised one-tenth of one percent of the Middle East landmass, and less than two percent of the region's total population.
Intensifying its demographic and geographic inferiority, Israel stretched 250 miles from the Red Sea port of Eilat in the south to the village of Metulla on the border with Syria and Lebanon in the north. That sliver of a country included a coastal waist just above its most populous point - Tel Aviv and its suburbs - pinched to only nine miles wide. Israel's foreign minister and ambassador to the United Nations, Abba Eban, noted in an oft-cited December 5, 1969 interview with the German newspaper Der Spiegel that his country's precarious pre-'67 boundaries had carried with them the memory of Auschwitz - the notorious World War II Nazi concentration camp in Poland.
The standing army had grown to roughly 75,000, with nearly 1,000 tanks and 175 jet planes. Nevertheless, the Arab armies combined "could field 900 combat aircraft, over 5,000 tanks and half a million men" (Six Days of War: June 1967 and the Making of The Modern Middle East, Michael B. Oren, Oxford University Press, 2002, page 164). Meanwhile, anti-Israel Palestinian terrorism - instigated or tolerated by Syria, Egypt, and Jordan - intensified between April, 1966 and April, 1967. So did direct attacks by Syria.
The vulnerable armistice lines reminded Israelis that they and their state literally lived on the edge. Syria on the Golan Heights overlooked northern Israel and Lake Kinneret (The Sea of Galilee) the country's main water source. Jordan on the hills of the West Bank (Samaria and Judea) dominated the coastal plain. Egypt in the Gaza Strip was only 30 miles from Tel Aviv's southern suburbs. Arab refusal to recognize Israel (hence the Arabs' insistence in 1949 and 1950 on armistice lines rather than permanent borders) and frequent pledges to destroy it made the possibility of a sudden attack plausible. Leaders and citizens lived with a recurrent nightmare: the country cut in two and prevented from successfully mobilizing reserves or regrouping for a counter-attack.
In addition to demographic and geographic vulnerability, on top of reiterated Arab threats of destruction, Israelis faced the failure of international guarantees made after the 1956 Sinai Campaign. In May, 1967, the United Nations Emergency Force in Sinai, stationed after '56 to help keep peace, complied with Egypt's demand that it withdraw. Egyptian leader Gamal Abdel Nasser then began to move 80,000 troops, 550 tanks and nearly 1,000 artillery pieces into the peninsula. "Israel then made what has since been judged a psychological mistake. Hoping to assert her peaceful intentions, and to calm the jittery atmosphere created by Arab - and Soviet - accusations of an imminent Israeli attack on Syria, she held her May 15 Independence Day parade without the usual large numbers of tanks and heavy artillery" (Israel: A History, Martin Gilbert, Doubleday: Black Swan, 1999, page 366). The move backfired.
Egypt proceeded to close the Strait of Tiran, blockading Eilat in violation of post-'56 international assurances of free passage. Though diplomacy to re-open the strait stalled, France and even the United States warned Israel not to act first. Israeli leaders recognized that the blockade, a casus belli in its own right, represented an even greater threat - Arab dismissal of Israeli deterrence in general. This put not only free shipping, but also the country itself at risk.
Meanwhile, "converging on Sinai were military contingents from countries that only days before had regarded Egypt as a mortal enemy, from Morocco and Libya, Saudi Arabia and Tunisia. Even the Syrians finally relented and agreed to send a brigade to fight alongside the Iraqis in Jordan .... Added to this was immense political might. Arab oil producers had agreed to boycott any countries that assisted Israel .... The Suez Canal, warned Nasser, could be blocked." The Arab world "felt bound by a single, exalted effort, as expressed by President 'Aref of Iraq: 'Our goal is clear - to wipe Israel off the face of the map" (Oren.).
One Israeli, Lt. Yossi Peled (later a general), recalled the feeling in the weeks before the war: "We had seen photographs of the victims of Egyptian gas attacks in Yemen [during Cairo's intervention in Yemeni wars of the early 1960s] .... We had already started thinking in terms of annihilation, both national and personal" (Oren).
During the nerve-wracking Hamtana, "the waiting period" of May 23 to June 4, "the mood of the people of Israel came as near to despair as it had ever come .... A great bandwagon formed. [Jordan's King] Hussein came to Cairo and placed his armed forces under Egyptian command. The radios of the Arab world dropped their attacks on one another and concentrated their attention on Israel in a paroxysm of triumphant hate," journalist, diplomat and historian Conor Cruise O'Brien has written (The Siege: The Saga of Israel and Zionism, Touchstone: Simon and Schuster, 1987, page 413).
Meanwhile, Israeli Prime Minister Levi Eshkol's responses to Egyptian provocations had "remained very mild, to the fury and disgust of many Israelis." Though Eshkol had diplomatic and military reasons to wait - including to gain British and especially American understanding if not intervention in reopening the straits and to gain time for Israel's citizen-army to mobilize - "the contrast between Eshkol and Nasser was profoundly distressing for Israelis" (O'Brien).
On May 31, U.S. Secretary of State Dean Rusk told a congressional committee that the United States was not planning a separate military intervention in the Middle East, "but only within the framework of the United Nations ...." Meaning, there would be no such intervention. Rusk added that "I don't think it is our business to restrain anyone." Washington signaled that it understood Israel had tried diplomacy and that diplomacy would not roll back Egypt actions. "The Hamtana was ending" (O'Brien).
In response to domestic political pressure, on June 1 Moshe Dayan replaced Eshkol in the cabinet as defense minister, though not as prime minister. Opposition leader Menachem Begin was brought in as the cabinet expanded to a national unity government. Four days later, Israeli planes destroyed the Egyptian Air Force on the ground, then defeated the Syrian and Jordanian air forces before breaking through on all three land fronts. Personal and national feelings of hopelessness had been vanquished, Middle East reality and Israel's place in it, dramatically changed.