In 1963, with the help of the Soviet Union, the Arab nations who needed plausible deniability when it came to terror attacks aimed at the Jewish State, created a front called the Palestinian Liberation Organization. The PLO was established to be the organization that would serve as the face of the struggle against Israel, and the group that would take responsibility for attacks against the Jewish State despite most of the attacks originating in the power halls of Arab countries.
The targets of the PLO were always civilians. Egypt's dictator, Gamal Abdul Nasser, who led the effort to create this entity and was advised by the Soviets in doing so, had two goals; to attack Israel and undermine the Jordanian King Hussein who Nasser viewed as a threat to his plans to reign over the Arab world. Nasser had thought the Soviets would help him gain control of the region if he did their bidding. King Hussein as a result of the attacks stemming from Nasser's new terrorist front, closed the PLO offices in Jerusalem which they controlled and arrested many of its members.
In 1965, Arab leaders met in Casablanca, Morocco to discuss plans to go to war with Israel. Unbeknownst to the Arab leaders, they were secretly being recorded, by the host of the summit, King Hassan II of Morocco. Hassan passed the recordings to the Israelis, making them aware of the plans and giving them time to prepare. Meanwhile, Syria was bombing the Golan Heights causing many Israelis to flee to neighboring kibbutzim that were equipped with bomb shelters. The surrounding Arab nations, Lebanon, Jordan, Syria, and Egypt were preparing for what Nasser called “total war.” Israel retaliated against the Arab forces that were gathering on their borders, and as a result, Egypt issued a blockade and closed all shipments bound for Eilat through the Red Sea.
In 1967, Nasser amassed 465,000 troops and inundated the Southern border of Israel. Seeing this, the United States tried to prevent war by establishing an embargo on the weapons trade with Israel. While the U.S. was trying to placate the Arabs by denying Israel defensive weapons, the Soviets were providing the Arabs with a massive amount of supplies. Israel, in a preemptive strike, launched a surprise attack that destroyed more than half the Egyptian aircraft in just one morning. Israel caught the Arabs by surprise, attacking them while they were eating breakfast. The result of this strike was a series of tank battles between Egyptian and Israeli forces in the deserts of Sinai.
In June, Jordan prepared to send paratroopers to assault the Western part of Jerusalem which Israel controlled. When the paratroopers arrived, a guerilla war broke out on the streets with citizens and the Israeli military both fighting off the Jordanian soldiers. Furthermore, a battle broke out in an area called 'Ammunition Hill' which was a British-era, fortified arms depot that the Jordanian army was using. This battle marked one of the bloodiest battles of the war and one of the deadliest in Israel's history. The commanders who were fighting against the Jordanian defenses encircled the Old City which Jordan had controlled, and the Jordanian forces retreated. Israel had reclaimed the whole of Jerusalem and reunified the city. In the next 48 hours, Israel followed the retreating Jordanian forces through the West Bank until the Jordanian forces had crossed to the Eastern Bank of the Jordan River. During this counter-offensive by Israel, 325,000 Palestinians living in the West Bank had fled to Jordan. Israel offered these refugees help to resettle, but they refused. To this day, not one of these refugees or their descendants is considered a citizen of Jordan.
Meanwhile, on the northern border of Israel, after heavy bombardment, Israeli forces succeeded in breaking the Syrian forces. This victory came at a very high cost with 777 Israelis killed. Consequently, Israel captured Sinai, the Gaza Strip, and the West Bank, nearly tripling the size of Israel from the 1948 partition. Most importantly, the ancient city of Jerusalem was once again in Jewish hands and Israel invited all Christians, Muslims, and Jews to come and pray freely - something that the Jordanians forbade during their occupation of the city.