[12] The Imam escaped to the Saudi Arabian border where he rallied popular support from northern Zaydi tribes to retake power, and the conflict rapidly escalated to a full-scale civil war.

The surprising removal of Sallal on November 5 by Yemeni dissidents, who were supported by republican tribesmen, resulted in an internal shift of power in the capital, as the royalists were approaching from the north.

Fights erupted between tribal chieftains, and al-Badr unsuccessfully tried to buy off the dissidents by promising "reforms",[20] including the appointment of a representative council, more army pay, and promotions.

Nasser was also keen to maintain his reputation as an Arab nationalist, setting his sights on expelling British forces from South Yemen, including Britain's presence in the strategic port city of Aden.

The armory was perhaps the easiest target, as a written order from Sallal was sufficient to open the storage facility, beat the royalists, and secure rifles, artillery, and ammunition for the revolutionaries.

[26] Egyptian General Ali Abdul Hameed was dispatched by plane, and arrived in Yemen on September 29 to assess the situation and needs of the Yemeni Revolutionary Command Council.

[27] Saudi Arabia, fearing Nasserist encroachment, moved troops along its border with Yemen, as King Hussein of Jordan dispatched his army chief of staff for discussions with al-Badr's uncle, Prince Hassan.

A letter, which was kept confidential until January 1963, from President Kennedy to Faisal dated October 25, stated: "You may be assured of full US support for the maintenance of Saudi Arabian integrity".

[45] In the battle of El-Argoup, 25 miles (40 km) southeast of San'a, 500 royalists under Prince Abdullah's command attacked an Egyptian position on top of a sheer-sided hill that was fortified with six Soviet T-54 tanks, a dozen armored cars and entrenched machine guns.

[47] On June 12, about 4,000 Egyptian infantry, reinforced by the republican army and mercenaries from the Aden protectorate, invaded the town of Beit Adaqah, about 30 miles (48 km) west of San'a, where Prince Abdullah held a front extending from the Hodeida road, through Kawakaban Province, to southern Hajjah.

Noman's first act was to name a new 15-man Cabinet, maintaining an even balance between Yemen's two main tribal groupings, the Zaidi Shias from the mountains, who were mostly royalist, and the Shafi'i Sunnis, who were mostly republican.

The Soviets were also willing to aid Nasser with arms and equipment in Yemen, but feared that a widening of the conflict to Saudi Arabia would lead to a "hot war" confrontation in the Middle East.

Sallal arrested about 140 suspects, including Mohamed Ruwainy, the ex-minister for tribal affairs, and Colonel Hadi Issa, former deputy chief of staff of the armed forces.

Sallal accused Ruwainy and Issa of organizing a "subversive network seeking to plunge the country into terrorism and panic" and planning a campaign of assassination, financed by Saudi Arabia, Britain, Israel and the US.

[74] By 1967, Egyptian forces relied exclusively on defending a triangle linking Hodeida, Taiz, and San'a, while striking southern Saudi Arabia and North Yemen with air sorties.

[81] Egypt imposed higher taxes on its middle and upper classes, raised workers' compulsory monthly savings by 50%, reduced overtime pay, cut the sugar ration by a third, and curtailed practically all major industrial programs.

[89] On November 5, 1967, Yemeni dissidents, supported by republican tribesmen called down to San'a, moved four tanks into the city's dusty squares, took over the presidential palace and announced over the government radio station that Sallal had been removed "from all positions of authority".

In 1965, the US authorized an agreement with the Corps of Engineers to supervise the construction of military facilities and, in 1966, it sponsored a $100 million program that provided the Saudi forces with combat vehicles, mostly trucks.

Mercenaries from France, Belgium and England, who had fought in Rhodesia, Malaya, Indochina, and Algeria were sent to assist the imam in planning, training, and giving the irregular forces the ability to communicate with one another and the Saudis.

[3] Between 1962 and 1965, Britain engaged in covert operations in support of Royalist forces fighting the Egyptian-backed Republican regime that had seized power in Yemen's capital, Sana'a, in September 1962.

[105] Hart-Davis further claims that success was finally achieved by an adviser to the mercenaries, the MP Neil "Billy" McLean, who privately (without the British government's knowledge) flew to Tel Aviv to meet Moshe Dayan, defense minister, and Meir Amit, head of Mossad.

[106] According to Haaretz, Tony Boyle[107] contacted David Karon, the head of the Middle East department in the Tevel (Cosmos) section of the Mossad, and met with IAF commander Ezer Weizman and his officers.

[109] According to Hart-Davis, the Israelis had systematically concealed the source of the weapons delivered by the mercenaries, brazing out all the serial numbers, using Italian parachutes, and even ensuring that the packaging consisted of wood-shavings from Cyprus.

Prime Minister Alec Douglas-Home replied to Michael Foot's parliamentary question on May 14, 1964, having, according to Hart-Davis "to skate across thin ice", by saying "Our policy towards the Yemen is one of non-intervention in the affairs of that country.

On July 22, 1964, Douglas-Home sent a memorandum to Foreign Secretary Rab Butler in which he "decreed that the United Kingdom should 'make life intolerable' for Nasser, 'with money and arms', and that this 'should be deniable if possible'".

The September 1962 coup d'état in Yemen was perceived a threat to the monarchies in both Saudi Arabia and Jordan, prompting shipments of weapons to the royalists, beginning October 1.

[2] Anwar Sadat was convinced that a regiment reinforced with aircraft could firmly secure Al-Sallal and his free officer movement, but within three months of sending troops to Yemen, Nasser realized that this would require a larger commitment than anticipated.

President Kennedy sent only a wing of jet fighters and bombers to Dhahran Airbase, demonstrating to Nasser the seriousness of American commitment to defending US interests in Saudi Arabia.

Sallal called the talks "a complete success", while al-Badr stated that "It is essential that the conflict which has devastated our beloved country be brought to an end by peaceful negotiations between the Yemeni people themselves.

At the Egyptians' request, due to assassination rumors, the banners and flags normally displayed to celebrate a visiting dignitary were omitted, the sidewalks were cleared of people, and the car was a special bulletproof model.