[10] On 17 September 1970, the Jordanian Army surrounded cities with a significant PLO presence, including Amman and Irbid, and began targeting fedayeen posts that were operating from Palestinian refugee camps.

However, the Jordanian military attacked again in January 1971, and the fedayeen were driven out of the cities, one by one, until 2,000 surrendered after they were encircled during the Ajlun offensive on 23 July, formally marking the end of the conflict.

[15] King Hussein considered that the Palestinian problem would remain the country's overriding national security issue;[15] he feared an independent West Bank under PLO administration would threaten the autonomy of his Hashemite kingdom.

[20] After Jordan lost the West Bank, Fatah (under the PLO) stepped up their guerrilla attacks against Israel from Jordanian soil, making the border town of Karameh their headquarters.

[21] On 18 March 1968, an Israeli school bus was blown up by a mine near Be'er Ora in the Arava, killing two adults and wounding ten children—the 38th Fatah operation in little more than three months.

[22] On 21 March, Israel Defense Forces (IDF) units entered Jordan and launched a reprisal attack on Karameh that developed into a full-scale battle that lasted a day.

[24] Both sides declared victory: Israel had fulfilled its objective of destroying the Karameh camp, but failed to capture Arafat; while Jordan and the PLO had exacted relatively heavy Israeli casualties.

[32] Immediately after the incident, a seven-point agreement was reached between King Hussein and Palestinian organizations that restrained unlawful and illegal fedayeen behavior against the Jordanian government.

[38] They also stirred up conservative and religious feelings with provocative anti-religious statements and actions, such as putting up Marxist and Leninist slogans on mosque walls.

Their very presence in Amman, far from the battlefield, seemed like a challenge to the regime.Palestinians claimed there were numerous agents provocateurs from Jordanian or other security services present among the fedayeen, deliberately trying to upset political relations and provide justification for a crackdown.

[35] There were frequent kidnappings and acts of violence against civilians:[35] Chief of the Jordanian Royal Court (and subsequently Prime Minister) Zaid al-Rifai claimed that in one extreme instance "the fedayeen killed a soldier, beheaded him, and played football with his head in the area where he used to live".

[39] Upon his return, he published a ten-point edict restricting activities of the Palestinian organizations, which included prohibition of the following: carrying arms publicly, storing ammunitions in villages, and holding demonstrations and meetings without prior governmental consent.

[39] Libya, Saudi Arabia and Kuwait, who were openly supporting the fedayeen, sent Jordan financial subsidies, placing Hussein in a difficult position.

[43] Bedouin units of the army retaliated for the assassination attempt against their king by shelling Al-Wehdat and Al-Hussein camps, which escalated into a conflict that lasted three days.

[43] An Israeli army meeting deliberated on events in Jordan; according to the director of Israel's Military Intelligence, there were around 2,000 fedayeen in Amman armed with mortars and Katyusha rockets.

[44] Henry Kissinger, President Nixon's security advisor, gave the following assessment of the events in Jordan:[45] The authority and prestige of the Hashemite regime will continue to decline.

"[4] Paradoxically, Arafat had cautioned Habash and Hawatmeh, the respective leaders of the PFLP and the DFLP, from provoking the regime, as it enjoyed military superiority and could terminate their existence in Jordan at any time.

[50] Al-Jazy, the perceived pro-Palestinian newly appointed army chief of staff, resigned on 9 September in the midst of the hijacking crisis, and was replaced by Habis Majali, who was brought in from retirement.

[51] Natheer Rasheed, the intelligence director who had been appointed a month earlier, claimed that Al-Jazy was paid 200,000 Jordanian dinars, and that his resignation letter was written by the PLO.

[51] He argues that Hussein was patient so that he could demonstrate that he had done everything he could to avoid bloodshed, and that confrontation only came after all other options had been exhausted, and after public opinion (both international and local) had tipped against the fedayeen.

[52] Amer Khammash, Habis Majali, Sharif Shaker, Wasfi Tal, and Zaid al-Rifai were among those who were present; for some time they had been urging Hussein to sort out the fedayeen.

"[52] On 17 September, the 60th Armoured Brigade entered the capital Amman from different directions and shelled the Wehdat and Hussein refugee camps where the fedayeen were based with tanks, artillery and mortars.

[53] David Raab, one of the plane hijacking hostages, described the initial military actions of Black September:[54] We were in the middle of the shelling since Ashrafiyeh was among the Jordanian Army's primary targets.

Suddenly, the shelling stopped.Hussein arranged a cabinet meeting on the evening of the Syrian incursion, leaving them to decide if Jordan should seek foreign intervention.

Military commanders also prepared contingency plans to occupy Jordanian territory–including the Gilead Heights, Karak and Aqaba–in case the country disintegrated and there was a land-grab by its Iraqi, Syrian and Saudi Arabian neighbors .

[68] In the period following the ceasefire, Hussein publicly revealed that the Jordanian army had uncovered around 360 underground PLO bases in Amman, and that Jordan held 20,000 detainees, among whom were "Chinese advisors".

[71] The head of a Pakistani training mission to Jordan, Brigadier Muhammad Zia-ul-Haq (later Chief of Army Staff and President of Pakistan), was involved on the Jordanian side.

[75] On 3 August 1972, PMOI operatives bombed the Jordanian embassy in Tehran during King Hussein's state visit as an act of "revenge" for the events of Black September.

For instance, Nayef Hawatmeh, the head of the Democratic Front for the Liberation of Palestine (DFLP), one of the most radical Palestinian organizations, comes from Salt in the East Bank.

[83] On 28 November 1971, four of the group's members assassinated Prime Minister Wasfi Tal in the lobby of the Sheraton Cairo Hotel in Egypt while he was attending an Arab League summit.