North Yemen Civil War The North Yemen Civil War ( Arabic : ثورة 26 سبتمبر ) was fought in North Yemen between royalists of the Mutawakkilite Kingdom of Yemen and factions of the Yemen Arab Republic from 1962 to 1970 . The war began with a coup d ' état carried out by the republican leader , Abdullah as - Sallal , which dethroned the newly crowned Imam al - Badr and declared Yemen a republic under his presidency . The Imam escaped to the Saudi Arabian border and rallied popular support . On the royalist side Jordan and Saudi Arabia supplied military aid , and Britain gave covert support , while the republicans were supported by Egypt and allegedly received warplanes from the Soviet Union . Both foreign irregular and conventional forces were involved . The Egyptian President , Gamal Abdel Nasser , supported the republicans with as many as 70 , 000 Egyptian troops and chemical weapons . Despite several military moves and peace conferences , the war sank into a stalemate . Egypt ' s commitment to the war is considered to have been detrimental to its performance in the Six - Day War of June 1967 , after which Nasser found it increasingly difficult to maintain his army ' s involvement and began to pull his forces out of Yemen . Egyptian military historians refer to the war in Yemen as their Vietnam , and historian Michael Oren ( current Israeli Ambassador to the U . S ) wrote that Egypt ' s military adventure in Yemen was so disastrous that " the imminent Vietnam War could easily have been dubbed America ' s Yemen . " Background . Yemen . Imam Ahmad bin Yahya , who had inherited the Yemeni throne in 1948 , was known as " Ahmad the devil " by his enemies . In 1955 , Iraq - trained Colonel Ahmad Thalaya led a revolt against him . A group of soldiers under his command surrounded the royal palace of Al Urdhi at Taiz , a fortified stronghold where the Imam lived with his harem , the royal treasure , an arsenal of modern weapons , and a 150 strong palace - guard , and demanded Ahmad ' s abdication . Ahmad agreed , but demanded that his son , Imam al - Badr succeed him . Thalaya refused , preferring the King ' s half brother , the Emir Saif el Islam Abdullah , the 48 - year - old Foreign Minister . While Abdullah began forming a new government , Ahmad opened the treasury coffers and secretly began buying off the besieging soldiers . After five days , the number of besiegers was reduced from 600 to 40 . Ahmad then came out of the palace , wearing a devil ' s mask and wielding a long scimitar , terrifying the besiegers . He slashed two sentries dead before exchanging the sword for a sub - machine gun and leading his 150 guards onto the roof of the palace to begin a direct attack on the rebels . After 28 hours , 23 rebels and one palace guard were dead and Thalaya gave up . Abdullah was later reported executed , and Thalaya was publicly decapitated . In March 1958 , al - Badr arrived in Damascus to tell Nasser of Yemen ' s adherence to the UAR . However , Ahmad was to keep his throne and his absolute power , and the arrangement constituted only a close alliance . In 1959 Ahmad went to Rome to treat his arthritis , rheumatism , heart trouble and , reportedly , drug addiction . Fights between tribal chieftains erupted , and al - Badr unsuccessfully tried to buy off the dissidents by promising " reforms " , including the appointment of a representative council , more army pay and promotions . Upon his return , Ahmad swore to crush the " agents of the Christians " . He ordered the decapitation of one of his subjects and the amputation of the left hand and right foot of 15 others , in punishment for the murder of a high official the previous June . Al - Badr was only rebuked for his leniency , but the Yemeni radio stopped broadcasting army officers ' speeches , and talks of reforms were silenced . In June 1961 , Ahmad was still recovering from an assassination attempt four months earlier , and moved out of the capital , Taiz , into the pleasure palace of Sala . Already Defense and Foreign Minister , Badr became acting Prime Minister and Interior Minister as well . Despite being Crown Prince , al - Badr still needed to be picked by the Ulema in San ' a . Al - Badr was not popular with the Ulema due to his association with Nasser , and the Ulema had refused Ahmad ' s request to ratify Badr ' s title . Imam Ahmad died on September 18 , 1962 , and was succeeded by his son , Imam al - Badr . One of al - Badr ' s first acts was to appoint Colonel Abdullah Sallal , a known socialist and Nasserist , as commander of the palace guard . Egypt . Nasser had looked to a regime change in Yemen since 1957 and finally put his desires into practice in January 1962 by giving the Free Yemen Movement office space , financial support , and radio air time . Anthony Nutting ' s biography of Gamal Abdel - Nasser identifies several factors that led the Egyptian President to send expeditionary forces to Yemen . These included the unraveling of the union with Syria in 1961 , which dissolved his United Arab Republic ( UAR ) , damaging his prestige . A quick decisive victory in Yemen could help him recover leadership of the Arab world . Nasser also had his reputation as an anti - colonial force , setting his sights on ridding South Yemen , and its strategic port city of Aden , of British forces . Mohamed Heikal , a chronicler of Egyptian national policy decision making and confidant of Nasser , wrote in " For Egypt Not For Nasser " , that he had engaged Nasser on the subject of supporting the coup in Yemen . Heikal argued that Sallal ' s revolution could not absorb the massive number of Egyptian personnel who would arrive in Yemen to prop up his regime , and that it would be wise to consider sending Arab nationalist volunteers from throughout the Middle East to fight alongside the republican Yemeni forces , suggesting the Spanish Civil War as a template from which to conduct events in Yemen . Nasser refused Heikal ' s ideas , insisting on the need to protect the Arab nationalist movement . Nasser was convinced that a regiment of Egyptian Special Forces and a wing of fighter - bomber s would be able to secure the Yemeni republican coup d ' état . Nasser ' s considerations for sending troops to Yemen may have included the following : ( 1 ) impact of his support to the Algerian War of Independence from 1954 – 62 ; ( 2 ) Syria breaking up from Nasser ' s United Arab Republic ( UAR ) in 1961 ; ( 3 ) taking advantage of a breach in British and French relations , which had been strained by Nasser ' s support for the FLN in Algeria and primarily for his efforts to undermine the Central Treaty Organization ( CENTO ) , which caused the downfall of the Iraqi monarchy in 1958 ; ( 4 ) confronting imperialism , which Nasser saw as Egypt ' s destiny ; ( 5 ) guaranteeing dominance of the Red Sea from the Suez Canal to the Bab - el - Mandeb strait ; ( 6 ) retribution against the Saudi royal family , whom Nasser felt had undermined his union with Syria . History . Coup d ' état . Plot . At least four plots were going on in San ' a . One was headed by Lieutenant Ali Abdul al Moghny . Another one was conceived by Sallal . His plot merged into a third conspiracy prodded by the Hashid tribal confederation in revenge for Ahmad ' s execution of their paramount sheik and his son . A fourth plot was shaped by several young princes who sought to get rid of al - Badr but not the imamate . The only men who knew about those plots were the Egyptian chargé d ' affaires , Abdul Wahad , and al - Badr himself . The day after Ahmad ' s death , al - Badr ' s minister in London , Ahmad al Shami , sent him a telegram urging him not to go to San ' a to attend his father ' s funeral because several Egyptian officers , as well as some of his own , were plotting against him . Al - Badr ' s private secretary did not pass this message to him , pretending he did not understand the code . Al - Badr may have been saved by the gathering of thousands of men at the funeral . Al - Badr learned of the telegram only later . A day before the coup Wahad , who claimed to have information from the Egyptian intelligence service , warned al - Badr that Sallal and fifteen other officers , including Moghny , were planning a revolution . Wahad ' s purpose was to cover himself and Egypt in case the coup failed , to prompt the plotters into immediate action , and drive Sallal and Moghny into a single conspiracy . Sallal got imamic permission to bring in the armed forces . Then , Wahad went to Moghny , and told him that al - Badr had somehow discovered the plot , and that he must act immediately before the other officers would be arrested . He told him that if he could hold San ' a , the radio and the airport for three days , the whole of Europe would recognize him . Sallal ordered that the military academy in San ' a go on full alert — opening all armories and issuing weapons to all junior officers and troops . On the evening of September 25 , Sallal gathered known leaders of the Yemeni nationalist movement and other officers who had sympathized or participated in the military protests of 1955 . Each officer and cell would be given orders and would commence as soon as the shelling of al - Badr ' s palace began . Key areas that would be secured included Al - Bashaer palace ( al - Badr ' s palace ) , Al - Wusul palace ( Reception area for dignitaries ) , the radio station , the telephone exchange , Qasr al - Silaah ( The Main Armory ) , and the central security headquarters ( Intelligence and Internal Security ) . Execution . At 10 : 30 p . m . , al - Badr heard tanks moving through the nearby streets , and reckoned that they were the ones Sallal had asked to move . At 11 . 45 p . m . the army began shelling the palace . Al - Badr seized a machine gun and began firing at the tanks , although they were out of range . Moghny sent an armored car to Sallal ' s house and invited him to the headquarters , where he asked him to join the revolution . Sallal agreed , on condition that he would be President . Moghny agreed . The coup d ' état was carried out with 13 tanks from the Badr Brigade , six armored cars , two mobile artillery cannons , and two anti - air guns . Command and control of the forces loyal to the coup would take place at the Military Academy . A unit of revolutionary officers accompanied by tanks headed towards Al - Bashaer Palace . By microphone , they voiced an appeal to the imamate Guard for tribal solidarity and to surrender Imam al - Badr , who would be sent peacefully into exile . The imamate Guard refused to surrender and opened fire , prompting the revolutionary leaders to respond with tank and artillery shells . The rebels planned to deploy tanks and artillery in the coup . The battle at the palace continued until guards surrendered to the revolutionaries the following morning . The radio station was first to fall , secured after a loyalist officer was killed and resistance collapsed . 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 resistance . The telephone exchange likewise fell without any resistance . At the Al - Wusul Palace , revolutionary units remained secure under the guise of granting and protecting diplomats and dignitaries staying there to greet the new Imam of Yemen . By late morning on September 26 , all areas of San ' a were secure and the radio broadcast that Imam al - Badr had been overthrown by the new revolutionary government in power . Revolutionary cells in the cities of Taiz , Al - Hujja and the port city of Hodeida then began securing arsenals , airports and port facilities . Coup aftermath . Al - Badr and his personal servants managed to escape through a door in the garden wall in the back of the palace . Because of the curfew declared , they had to avoid the main streets . They decided to escape individually and meet in the village of Gabi al Kaflir , where they were reunited after a forty - five minute walk . Sallal had to defeat a fellow revolutionary , Al - Baidani , an intellectual holding a doctorate degree , who did not share in Nasser ' s vision . On September 28 , the radio announced al - Badr ' s death . Sallal gathered tribesmen in San ' a and proclaimed : " The corrupt monarchy which ruled for a thousand years was a disgrace to the Arab nation and to all humanity . Anyone who tries to restore it is an enemy of God and man ! " By then , he had learned that al - Badr was still alive and had made his way to Saudi Arabia . Egyptian General Ali Abdul Hameed was dispatched by plane , and arrived on September 29 to assess the situation and needs of the Yemeni Revolutionary Command Council . Egypt sent a battalion of Special Forces ( Saaqah ) on a mission to act as personal guards for Sallal . They arrived at Hodeida on October 5 . Fifteen days after he had left San ' a , al - Badr sent a man ahead to the Saudi Arabia to announce that he was alive . He then went there himself , crossing the border near Khobar , at the north - eastern edge of the kingdom . Diplomacy attempts . Saudi Arabia , fearing Nasserist encroachment , moved troops along its border with Yemen , as the Jordanian monarch dispatched his Army chief of staff for discussions with al - Badr ' s uncle , Prince Hassan . Between October 2 – 8 four Saudi cargo planes left Saudi Arabia loaded with arms and military material for Yemeni royalist tribesmen ; however , the pilots defected to Aswan . Ambassadors from Bonn , London , Washington D . C . and Amman supported the Imam while ambassadors from Cairo , Rome and Belgrade declared support for the republican revolution . The USSR was the first nation to recognize the new republic , and Nikita Khrushchev cabled Sallal : " Any act of aggression against Yemen will be considered an act of aggression against the Soviet Union . " The United States was concerned that the conflict might spread to other parts of the Middle East . President John F . Kennedy rushed off notes to Nasser , Feisal , Hussein and Sallal . His plan was that Nasser ' s troops should withdraw from Yemen while Saudi Arabia and Jordan halted their aid to the Imam . Nasser agreed to pull out his forces only after Jordan and Saudi Arabia " stop all aggressive operations on the frontiers " . Feisal and Hussein rejected Kennedy ' s plan , since it would involve US recognition of the " rebels " . They insisted that the US should withhold recognition of Sallal ' s Presidency since the Imam might still regain control of Yemen , and that Nasser had no intention of pulling out . The Saudis argued that Nasser wanted their oil fields and was hoping to use Yemen as a springboard for revolt in the rest of the Arabian peninsula . King Hussein of Jordan was also convinced that Nasser ' s target was Saudi Arabia ' s oil , and that if the Saudis went , he would be next . Sallal declared " I warn America that if it does not recognize the Yemen Arab Republic , I shall not recognize it ! " . US Chargé d ' Affaires in Taiz , Robert Stookey , reported that the republican regime was in full control of the country , except in some border areas . However , the British government was insisting on the strength of the Imam ' s tribal support . A letter written by President Kennedy to Faisal dated October 25 , which was kept confidential until January 1963 , said : " You may be assured of full US support for the maintenance of Saudi Arabian integrity " . American jet aircraft twice staged shows of force in Saudi Arabia . The first involved six F - 100 jets staging stunt - flying demonstrations over Riyadh and Jeddah ; on the second , two jet bombers and a giant jet transport , while returning to their base near Paris after a visit to Karachi , Pakistan , put on a demonstration over Riyadh . Sallal proclaimed Yemen ' s " firm policy to honor its international obligations " , including a 1934 treaty pledging respect for Britain ' s Aden Protectorate . Nasser promised to " start gradual withdrawal " of its 18 , 000 - man force , " provided Saudi and Jordanian forces also retire from border regions " , but would leave his technicians and advisers behind . On December 19 , the US became the 34th nation to recognize the Yemen Arab Republic . United Nations recognition followed that of the US by a day . The UN continued to consider the republic the only authority in the land and completely ignored the royalists . Britain , with its commitment to South Arabia and its base in Aden , considered the Egyptian invasion a real threat . Recognition of the republic posed a problem to several treaties Britain had signed with the sheiks and sultans of the South Arabian Federation . Saudi Arabia urged the British to identify themselves with the royalists . On the other hand , there were some in the British Foreign Office who believed Britain could buy security for Aden by recognizing the republic . However , Britain eventually decided not to recognize . Iran , Turkey and most of western Europe also withheld recognition . The republic did receive the recognition of West Germany , Italy , Canada and Australia , as well as the remaining Arab governments , Ethiopia and the entire communist bloc . A week after the American recognition , Sallal boasted at a military parade the republic had rockets that could strike " the palaces of Saudi Arabia " , and in early January the Egyptians again bombed and strafed Najran , a Saudi Arabian city near the Yemenite border . The US responded with another aerial demonstration over Jeddah and a destroyer joined on January 15 . The US reportedly agreed to send antiaircraft batteries and radar - control equipment to Najran . In addition , Ralph Bunche was sent to Yemen , where he met with Sallal and Egyptian Field Marshal Abdel Hakim Amer . On March 6 Bunche was in Cairo , where Nasser reportedly assured him that he would withdraw his troops from Yemen if the Saudis would stop supporting the royalists . Operation Hard - surface . While Bunche was reporting to UN Secretary - General U Thant , the United States Department of State sought the help of ambassador Ellsworth Bunker . His mission was based on a decision made by the National Security Council , which was conceived by McGeorge Bundy and Robert Komer . The idea behind what became known as " Operation Hard - surface " was to trade American protection ( or the appearance of it ) for a Saudi commitment to halt aid to the royalists , on the basis of which the Americans would get Nasser to withdraw his troops . The operation would consist of " eight little planes . " Bunker arrived in Riyadh on March 6 . Faisal refused Bunker ' s offer , which was also hitched to pledges of reform . The original instructions for Operation Hard - surface were that American planes would " attack and destroy " any intruders over Saudi air space , but were later changed to read that the Saudis could defend themselves if attacked . Bunker evidently stuck to the original formula and stressed that if only Faisal would halt his aid to the royalists , the US would be able pressure Nasser to withdraw . Faisal eventually accepted the offer , and Bunker went on to meet with Nasser in Beirut , where the Egyptian President repeated the assurance he had given Bunche . The Bunche and Bunker mission gave birth to the idea of an observer mission to Yemen , which eventually became the United Nations Yemen Observation Mission . The U . N . observer team , which would be set up by the former UN Congo commander , Swedish Major General Carl von Horn . His disengagement agreement called for ( 1 ) Establishment of a demilitarized zone extending twenty kilometers on either side of a demarcated Saudi Arabian Yemen border , from which all military equipment was to be excluded ; ( 2 ) Stationing of UN observers within this zone on both sides of the border to observe , report and prevent any continued attempt by the Saudis to supply royalist forces . On April 30 , von Horn was sent to discover what kind of force was required . A few days later , he met with Amer in Cairo and found out that Egypt had no intention of drawing all her troops from Yemen . After a few more days , he was told by the Saudi deputy Minister for Foreign Affairs , Omar Saqqaff , that the Saudis would not accept any attempt by Egypt to leave security forces after their withdrawal . Saudi Arabia had already been cutting back on its support to the royalists , in part because Egypt ' s projected plan for unity with Syria and Iraq made Nasser seem too dangerous . By that time , the war cost Egypt $ 1 , 000 , 000 a day and nearly 5 , 000 casualties . Though promising to remove her troops , Egypt had the privilege of leaving an unspecified number for the " training " of Yemen ' s republican army . In June , von Horn went to San ' a , unsuccessfully trying to achieve the objective of 1 ) ending Saudi aid to the royalists , 2 ) creating a 25 - mile demilitarized strip along the Saudi border , and 3 ) supervising the phased withdrawal of the Egyptian troops . In September , von Horn cabled his resignation to Thant , who announced that the mission would continue , due to " oral assurances " by Egypt and Saudi Arabia to continue financing it . The number of Egyptian troops increased , and in the end of January , the " Hard - surface " squadron was withdrawn after a wrangle with Faisal . On September 4 , 1964 , the UN admitted failure and withdrew its mission . Egyptian offensives . The Egyptian General Staff divided the Yemen War into three operational objectives . The first was the air phase , it began with jet trainers modified to strafe and carry bombs and ended with three wings of fighter - bombers , stationed near the Saudi - Yemeni border . Egyptian sorties went along the Tiahma Coast of Yemen and into the Saudi towns of Najran and Jizan . It was designed to attack royalist ground formations and substitute the lack of Egyptian formations on the ground with high - tech air power . In combination with Egyptian air strikes , a second operational phase involved securing major routes leading to San ' a , and from there secure key towns and hamlets . The largest offensive based on this operational tactic was the March 1963 " Ramadan Offensive " that lasted until February 1964 , focused on opening and securing roads from San ' a to Sadah to the North , and San ' a to Marib to the East . The success of the Egyptian forces meant that royalist resistance could take refuge in hills and mountains to regroup and carry out hit - and - run offensives against republican and Egyptian units controlling towns and roads . The third strategic offensive was the pacification of tribes and their enticement to the republican government , meaning the expenditures of massive amounts of funds for humanitarian needs and outright bribery of tribal leaders . Ramadan offensive . The Ramadan offensive began in February 1963 when Amer and Sadat arrived in San ' a . Amer asked Cairo to double the 20 , 000 men in Yemen , and in early February the first 5 , 000 of the reinforcement arrived . On February 18 a task force of fifteen tanks , twenty armored cars , eighteen trucks and numerous jeeps took off from San ' a ' moving northwards , heading for Sadah . More garrison troops followed . A few days later another task force , spearheaded by 350 men in tanks and armored cars , struck out from Sadah southeastwards toward Marib . The maneuvered into the Rub al - Khali desert , perhaps well into Saudi territory , and there they were built up by an airlift . Then they headed westwards . On February 25 they occupied Marib and on March 7 they took Harib . A royalist force of 1 , 500 men ordered down from Najran failed to stop them on their way out from Sadah . The royalist commander at Harib fled to Beihan , on the British - protected side of the border . In the battle of El Argoup , 25 miles 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 tank s , a dozen armored cars and entrenched machine guns . The royalists advanced in a thin skirmish line and were plastered by artillery , mortars and strafing planes . They replied with rifles , one mortar with 20 rounds , and a bazooka with four rounds . The battle lasted a week and cost the Egyptians three tanks , seven armored cars and 160 dead . The Egyptians were now in positions from which they could hope to interdict the royalist movement of supplies in the mountains north and east of San ' a ' . In the beginning of April the royalists held a conference with Faisal in Riyadh . They decided to adopt new tactics , including attempts to get supplies around the positions now held by the Egyptians by using camels instead of trucks to cross the mountains to reach the positions east of San ' a . Camel caravans from Beihan would swing into the Rub al - Khali and enter Yemen north of Marib . It was also decided that the royalists must now strengthen their operations west of the mountains with three " armies " . By the end of April , they began to recover and claimed to have regained some of the positions the Egyptians had taken in the Jawf , particularly the small but strategic towns of Barat and Safra , both in the mountains between Sadah and the Jawf , and were able to move freely in the eastern Khabt desert . In the Jawf they claimed to have cleaned up all Egyptian strong - points except Hazm , and in the west the town of Batanah . Haradh offensive . On June 12 , Egyptian infantry numbering at about 4 , 000 , reinforced by the republican army and mercenaries from the Aden protectorate invaded the town of Beit Adaqah , about thirty miles west of San ' a , where Prince Abdullah held a front extending from the Hodeida road , through Kawakaban province , to southern Hajjah . In two days , the attackers advanced about twelve miles , before being repelled by a counter - attack . The royalists admitted about 250 casualties . Next , the Egyptians attacked Sudah , about 100 miles north - west of San ' a . They used the unpopularity of the local royalist commander to bribe several local sheiks and occupied the town unopposed . After a month , the sheiks sent delegations to al - Badr soliciting pardons and asking for guns and money with which to fight the Egyptians . Al - Badr sent new forces and managed to regain the surroundings of Sudah , though not the town itself . On August 15 , the Egyptians launched an offensive from their major north - western base in Haradh . They had 1 , 000 troops and about 2 , 000 republicans . The plan , as interpreted by British intelligence , seemed to have been to cut the thirty - mile track southward through the mountains from the Saudi border at Khoubah to al - Badr ' s headquarters in the Qara mountains near Washa , and then to split into two task forces , one moving east through Washa to the headquarters and the other north - eastwards along the track to the Saudi border below the Razih mountains . The Egyptians began their move on Saturday morning , moving along the Haradh and Tashar ravines . On Saturday and Sunday afternoons they were caught in heavy rain and their vehicles , including twenty tanks and about forty armored cars sank axle deep into the mud . The defenders left them alone until Monday at dawn . Al - Badr left his headquarters at three that morning with 1 , 000 men to direct a counterattack in the Tashar ravine , while Abdullah Hussein attacked in the Haradh ravine . Meanwhile , the Egyptians had planned a coordinated drive from Sadah to the southwest , below the Razih mountains , hoping to link up with the force coming from Haradh . They were counting on a local sheik , whose forces were to supposed to join 250 Egyptian parachutists . The sheik failed to deliver , and the parachutists made their way back to Sadah , suffering losses from snipers on the way . Al - Badr had sent radio messages and summonses by runner in all directions calling for reinforcement . He asked reserve forces training in the Jawf to arrive in trucks mounting 55 - and 57 - millimeter cannon and 81 millimeter mortars and heavy machine guns . They arrived within forty - eight hours , in time to face the attackers . They outflanked the Egyptian columns , still stuck in mud in the ravines . They later announced they had knocked out ten of the Egyptian tanks and about half of their armored cars , and claimed to have shot down an Ilyushin bomber . The royalists also carried out two supporting movements . One was a raid on Jihana , in which several staff officers were killed . The second was an attempt , involving British advisors and French and Belgian mercenaries from Katanga , to bombard San ' a from a nearby mountain peak . Other diversionary operations included raids on Egyptian aircraft and tanks at the south airport of San ' a and a mortar at the Egyptian and republican residence in a suburb of Taiz . Although the Egyptians managed to drive al - Badr out of his headquarters to a cave on Jabal Shedah , they could not close the Saudi border . They declared victory on the radio and on the press , but were obliged to agree to a ceasefire on the upcoming Erkwit conference on November 2 . Alexandria summit and Erkwit ceasefire . In September , 1964 , Nasser and Faisal met in the Arab summit in Alexandria . By that time Egypt had 40 , 000 troops in Yemen and had suffered an estimated 10 , 000 casualties . In their official communiqué the two leaders promised to 1 ) cooperate fully to solve the existing differences between the various factions in Yemen , 2 ) work together in preventing armed clashes in Yemen , and 3 ) reach a solution by peaceful agreement . The communiqué was widely hailed in the Arab world , and Washington called it a " statesmanlike action " and a " major step toward eventual peaceful settlement of the long civil war . " Nasser and Faisal warmly embraced at Alexandria ' s airport and called each other " brother " . Faisal said he was leaving Egypt " with my heart brimming with love for President Nasser . " On November 2 , at a secret conference in Erkwit , Sudan , the royalists and republicans declared a ceasefire effective at 1 : 00 PM on Monday , November 8 . Tribesmen of both sides celebrated the decision until that day , and for two days after it went into effect , they fraternized at several places . On November 2 and 3 , nine royalists and nine republicans , with a Saudi and an Egyptian observer , worked out the terms . A conference of 168 tribal leaders was planned for November 23 . For the royalists , the conference was to become an embryo national assembly that would name a provisional national executive of two royalists , two republicans and one neutral , to administer the country provisionally and to plan a plebiscite . Until that plebiscite , which would decide whether Yemen would be a monarchy or a republic , both Sallal and al - Badr were to step aside . At the end of the two days the Egyptians resumed their bombing of royalist positions . The conference planned for November 23 was postponed to the 30th , then indefinitely . The republicans blamed the royalists for not arriving , while the royalists blamed the Egyptian bombings . Royalist offensive . Between December 1964 and February 1965 the royalists discerned four Egyptian attempts to drive directly into the Razih mountains . The intensity of these thrusts gradually diminished , and it was estimated that the Egyptians lost 1 , 000 men killed , wounded and taken prisoner . Meanwhile , the royalists were building up an offensive . The Egyptian line of communications went from San ' a to Amran , then Khairath , where it branched off north - eastwards to Harf . From Harf it turned due south to Farah , and then South - eastwards to Humaidat , Mutamah and Hazm . From Hazm it led south - eastwards to Marib and Harib . A military convoy went over this route twice a month . Since the royalists had closed the direct route across the mountains from San ' a to Marib , the Egyptians had no other way . The royalists under the command of Prince Mohamed ' s objective was to cut the Egyptians ' line and force them to withdraw . They intended to take over the garrisons along this line and establish positions from which they could interdict the Egyptian movement . They had prepared the attack with the help of the Nahm tribe , who tricked the Egyptians into believing that they were their allies and would take care of the mountain pass known as Wadi Humaidat themselves . The royalist deal was that the Nahm would be entitled to loot the ambushed Egyptians . The Egyptians may have suspected something was up , as they sent a reconnaissance aircraft over the area a day before the attack . The royalists thus occupied two mountains known as Asfar and Ahmar and installed 75 - Millimeter guns and mortars overlooking the Wadi . On April 15 , the day after the last Egyptian convoy went through , the royalists launched a surprise attack . Both forces numbered at only a couple of thousands . The guns positioned on Asfar and Ahmar opened fire , and then the Nahm came out from behind the rocks . Finally , Prince Mohamed ' s troops followed . This time , the royalists ' operation was fully coordinated by radio . Some of the Egyptians surrendered without resistance , others fled to Harah 800 yards to the north . Both sides brought reinforcements and the battle shifted between Harf and Hazm . Meanwhile , Prince Abdullah bin Hassan began to raid Egyptian positions north - east of San ' a at Urush , Prince Mohamed bin Mohsin was attacking the Egyptians with 500 men west of Humaidat , Prince Hassan struck out from near Sadah and Prince Hassan bin Hussein moved from Jumaat , west of Sadah , to within mortar - firing distance of the Egyptian airfield west of Sadah . Fifty Egyptians surrendered at Mutanah , near Humaidat . They were eventually allowed to evacuate to San ' a with their arms . Mohamed ' s policy was to keep officers as prisoners for exchange , and to allow soldiers to go in return for their arms . Three to five thousand Egyptian troops in garrisons on the eastern slopes of the mountains and in the desert now had to be supplied entirely by air . Stalemate . The royalist radio tried to widen the split in republican ranks by promising amnesty to all non - royalists once the Egyptians were withdrawn . Al - Badr also promised a new form of government : " a constitutionally democratic system " ruled by a " national assembly elected by the people of Yemen " . At Sallal ' s request , Nasser provided him with ammunition and troop reinforcements by transport plane from Cairo . By August , the royalists had seven " armies " , each varying in strength between 3 , 000 and 10 , 000 men , with a total somewhere between 40 , 000 and 60 , 000 . There were also five or six times as many armed royal tribesmen , and the regular force under Prince Mohamed . In early June they moved into Sirwah in eastern Yemen . On June 14 they entered Qaflan and on July 16 they occupied Marib . According to official Egyptian army figures , they had 15 , 194 killed . The war was costing Egypt $ 500 , 000 a day . The royalists had lost an estimated 40 , 000 dead . In late August , Nasser decided to get the Soviets more involved in the conflict . He convinced them to cancel a $ 500 million debt he had incurred and provide military aid to the republicans . In early May , Sallal fired his Premier , General Hassan Amri , and appointed Ahmed Noman in his place . Noman was considered a moderate who believed in compromise . He had resigned as president of the republican Consultative Council in December in protest against Sallal ' s " failure to fulfill the people ' s aspirations " . Noman ' s first act was to name a new 15 - man Cabinet , maintaining an even balance between Yemen ' s two main tribal groupings , the mountain Zeidis , who are mostly royalist , and the Shafis , who are mostly republican . Nasser ' s " long - breath " strategy . Egypt had run up a foreign debt of nearly $ 3 billion , and the gap between exports and imports had widened to a record $ 500 million for 1965 . On Victory Day in Port Said , Nasser conceded that " We are facing difficulties . We must all work harder and make sacrifices . I have no magic button that I can push to produce the things you want " . Premier Zakaria Mohieddin raised Egypt ' s income tax , added a " defense tax " on all sales , and boosted tariffs on nonessential imports . He also hiked the cost of luxury goods 25 % and set low price ceilings on most foodstuffs . He sent 400 plainclothesmen to Cairo ' s to arrest 150 shopkeepers for price violations . In March 1966 , the Egyptian forces , now numbering almost 60 , 000 , launched their biggest offensive . The royalists counterattacked but the stalemate resumed . Egyptian - supported groups executed sabotage bombings in Saudi Arabia . In a speech on May Day , 1966 , Nasser said the war was entering a new phase . He launched what he called a " long - breath strategy . " The plan was to pare the army from 70 , 000 men to 40 , 000 , withdraw from exposed positions in eastern and northern Yemen , and tighten the hold on particular parts of Yemen : the Red Sea coastline ; a northern boundary that takes in the well - fortified town of Hajja and San ' a ; and the border with the South Arabian Federation , which was to become independent in 1968 . Nasser insisted that attacks on Najran , Qizan and other " bases of aggression " would continue , arguing that " these were originally Yemeni towns , which the Saudis usurped in 1930 " . Assistant Secretary of State for the Near East and South Asia , flew in for talks with both Faisal and Nasser . In Alexandria , Nasser refused to pull out his troops , despite the risk of losing part or all of a new $ 150 million US food - distribution program , and another $ 100 million worth of industrial - development aid . Later that month , Alexei Kosygin counseled Nasser not to risk a stoppage of the U . S . Food for Peace program because Russia could not afford to pay the bill . The Russians 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 . Nasser was warned that " the Soviet Union would be displeased to see an attack on Saudi Arabia . " In October , Sallal ' s palace in San ' a was shelled by a bazooka , and insurgents began targeting an Egyptian army camp outside the city and setting fire to Egyptian installations , killing a reported 70 Egyptian troops . 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 . Ruwainy , Issa and five others were executed , while eight others received prison sentences ranging from five years to life . In February , 1967 , Nasser vowed to " stay in Yemen 20 years if necessary " , while Prince Hussein bin Ahmed said " We are prepared to fight for 50 years to keep Nasser out , just as we did the Ottoman Turks . " Tunisia broke diplomatic relations with the republic , saying that the Sallal government no longer has power to govern the country . Sallal ' s chargé d ' affaires in Czechoslovakia flew to Beirut and announced that he was on his way to offer his services to the royalists . Nasser said that " As the situation now stands , Arab summits are finished forever . " Chemical warfare . The first use of gas took place on June 8 , 1963 against Kawma , a village of about 100 inhabitants in northern Yemen , killing about seven people and damaging the eyes and lungs of twenty - five others . This incident is considered to have been experimental , and the bombs were described as " home - made , amateurish and relatively ineffective " . The Egyptian authorities suggested that the reported incidents were probably caused by napalm , not gas . The Israeli Foreign Minister , Golda Meir , suggested in an interview that Nasser would not hesitate to use gas against Israel as well . There were no reports of gas during 1964 , and only a few were reported in 1965 . The reports grew more frequent in late 1966 . On December 11 , 1966 , fifteen gas bombs killed two people and injured thirty - five . On January 5 , 1967 , the biggest gas attack came against the village of Kitaf , causing 270 casualties , including 140 fatalities . The target may have been Prince Hassan bin Yahya , who had installed his headquarters nearby . The Egyptian government denied using poison gas , and alleged that Britain and the US were using the reports as psychological warfare against Egypt . On February 12 , 1967 , it said it would welcome a UN investigation . On March 1 , U Thant said he was " powerless " to deal with the matter . On May 10 , the twin villages of Gahar and Gadafa in Wadi Hirran , where Prince Mohamed bin Mohsin was in command , were gas bombed , killing at least seventy - five . The Red Cross was alerted and on June 2 , it issued a statement in Geneva expressing concern . The Institute of Forensic Medicine at the University of Berne made a statement , based on a Red Cross report , that the gas was likely to have been halogenous derivatives - phosgene , mustard gas , lewisite , chloride or cyanogen bromide . The gas attacks stopped for three weeks after the Six - Day War of June , but resumed on July , against all parts of royalist Yemen . Casualty estimates vary , and an assumption , considered conservative , is that the mustard and phosgene - filled aerial bombs caused approximately 1 , 500 fatalities and 1 , 500 injuries . Egyptian withdrawal . 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 . In August , 1967 , in order to make up for the 15 , 000 Egyptian killed , captured or missing , as a result of the Six - Day War , Nasser recalled 15 , 000 of his troops from Yemen . 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 . Only military expenditures were increased , by $ 140 million to an estimated $ 1 billion . Nasser also increased the price of beer , cigarettes , long - distance bus and railroad fares and admission to movies . Egypt was losing $ 5 , 000 , 000 a week in revenues from the closing of the Suez Canal , on the other side of which , the Israelis were sitting on the Sinai wells that had produced half of Egypt ' s oil supply . Egypt ' s hard - currency debt was now approaching $ 1 . 5 billion and its foreign - exchange reserves were down to $ 100 million . As part of the Khartoum Resolution of August , Egypt announced that it was ready to end the war in Yemen . Egyptian Foreign Minister , Mahmoud Riad , proposed that Egypt and Saudi Arabia revive their Jeddah Agreement of 1965 . Faisal expressed satisfaction with Nasser ' s offer , and al - Badr promised to send his troops to fight with Egypt against Israel , should Nasser live up to the Jeddah agreement Nasser and Faisal signed a treaty under which Nasser would pull out his 20 , 000 troops from Yemen , Faisal would stop sending arms to al - Badr , and three neutral Arab states would send in observers . Sallal accused Nasser of betrayal . Nasser unfroze more than $ 100 million worth of Saudi assets in Egypt , and Faisal denationalized two Egyptian - owned banks that he had taken over earlier that year . Saudi Arabia , Libya , and Kuwait agreed to provide Egypt with an annual subsidy of $ 266 million , out of which $ 154 million was to be paid by Saudi Arabia . Sallal ' s popularity among his troops declined , and after two bazooka attacks on his home by disaffected soldiers , he took Egyptian guards . He ordered the execution of his security chief , Colonel Abdel Kader Khatari , after Khatari ' s police fired into a mob attacking an Egyptian command post in San ' a , and had refused to recognize the committee of Arab leaders appointed at Khartoum to arrange peace terms . He also fired his entire Cabinet and formed a new one , installing three army men in key ministries , and took over the army ministry and the foreign ministry for himself . Meanwhile , Nasser announced the release of three republican leaders who had been held prisoner in Egypt for more than a year , and who were in favor of peace with the royalists . The three were Qadi Abdul Rahman Iryani , Ahmed Noman and General Amri . When Sallal met with Nasser in Cairo in early November , Nasser advised him to resign and go into exile . Sallal refused and went to Baghdad , hoping to get support from other Arab Socialists . As soon as he left Cairo , Nasser sent a cable to San ' a , instructing his troops there not to block an attempt at a coup . Siege of San ' a . On November 5 , 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 " . The coup went unopposed . In Baghdad , Sallal asked for political asylum , saying " every revolutionary must anticipate obstacles and difficult situations " . The Iraqi government offered him a home and a monthly grant of 500 dinars . The new republican government was headed by Qadi Abdul Rahman Iryani , Ahmed Noman and Mohamed Ali Uthman . The Prime Minister was Mohsin al - Aini . Noman , however , remained in Beirut . He was doubtful of his colleagues reluctance to negotiate with the Hamidaddin family , preferring to expel it instead . On November 23 , he resigned , and his place was taken by Hassan Amri . Prince Mohamed bin Hussein told the country ' s chiefs " We have money , and you will have your share if you join us . If not , we will go on without you " . The chiefs agreed to mobilize their tribes . 6 , 000 royalist regulars and 50 , 000 armed tribesmen known as " the Fighting Rifles " surrounded San ' a , captured its main airport and severed the highway to the port of Hodeida , a main route for Russian supplies . In a battle twelve miles east of the capital , 3 , 200 soldiers of both sides were killed , and an entire republican regiment reportedly deserted to the royalists . Bin Hussein gave them an ultimatum : " Surrender the city or be annihilated " . Iryani went to Cairo for what the Egyptian official press agency called " a medical checkup " . Foreign Minister Hassan Macky also left Yemen , leaving the government in charge of Amri . Amri declared a 6 p . m . curfew and ordered civilians to form militia units " to defend the republic " . In Liberation Square , six suspected royalist infiltrators were publicly executed by a firing squad , and their bodies were later strung up on poles . The republicans boasted a new air force , while the royalists claimed to have shot down a MiG - 17 fighter with a Russian pilot . The US State Department said that this claim , as well as reports of twenty - four MiGs and forty Soviet technicians and pilots who had arrived in Yemen , were correct . In January , the republicans were defending San ' a with about 2 , 000 regulars and tribesmen , plus armed townsmen and about ten tanks . They also had the backing of a score or more fighter aircraft piloted by Russians or Yemenis who passed a crash course in the Soviet Union . The city could still feed itself from the immediately surrounding countryside . Between 4 , 000 and 5 , 000 royalists suffered from republican air power , but had the advantage of high ground . However , they did not have enough ammunition , as the Saudis had halted arms deliveries after the Khartoum agreement and stopped financing the royalists after December . Final accords . By February 1968 , the siege was lifted and the republicans had essentially won the war . Meanwhile , the British had withdrawn from the Federation of South Arabia , which had now become South Yemen . The royalists remained active until 1970 . Talks between the two sides commenced while the fighting went on . The Foreign Minister , Hassan Makki , said " Better years of talk than a day of fighting " . In 1970 , Saudi Arabia recognized the Republic , and a ceasefire was effected . The Saudis gave the republic a grant of $ 20 million , which was later repeated intermittently , and Yemeni sheiks received Saudi stipends . By 1971 , both Egypt and Saudi Arabia had disengaged from Yemen . South Yemen formed a connection with the Soviet Union . In September 1971 , Amri resigned after murdering a photographer in San ' a , and more power was given to Iryani , the effective President . By then , the royalists were integrated into the new republic , except for al - Badr ' s family , and a consultative Council was established . Clashes along the border between the states rose , and in 1972 a small war broke . After the war , the tribes were better represented in the republican government . In 1969 sheihks were brought into the National Assembly and in 1971 into the Consultative Council . Under Iryani , the sheiks , particularly the ones who fought for the republicans and were close to the mediation attempt . By the end of the war there was a breach between the older and more liberal politicians and republican sheiks , and certain army sheiks and activists from South Yemen . In the summer of 1972 a border war broke and ended with a declaration from both North Yemen and South Yemen that they would reunite , but they did not . There were complaints in North Yemen about foreign influence by Saudi Arabia . Opposing forces . Royalists . Imam al - Badr led his campaign with the princes of the house of Hamidaddin . Those included Hassan bin Yahya , who had come from New York , Mohamed bin Hussein , Mohamed bin Ismail , Ibrahim al Kipsy , and Abdul Rahman bin Yahya . At fifty - six , Hassan bin Yahya was the oldest and most distinguished . Prince Hassan was made Prime Minister and Commander - in - Chief . The Imam was joined by his childhood pen pal , American Bruce Conde , who set up the post office and would later rise to the rank of general in the Royalist forces . In 1963 , the Saudis spent $ 15 million to equip royalist tribes , hire hundreds of European mercenaries , and establish their own radio station . Pakistan , which saw a chance to make money in the conflict , extended rifles to the royalists . Remnants of the Imam ' s Army also had elements of the Saudi National Guard fight alongside its ranks . Iran subsidized royalist forces on and off , as the Shah felt compelled to provide al - Badr ( a Shiite Zeidi ) with financing . The British allowed convoys of arms to flow through one of its allies in Northern Yemen , the Sheriff of Beijan , who was protected by the British administration in Aden . British military planes conduced night operations to resupply al - Badr ' s forces . The MI6 was responsible for contacting the royalists , and used the services of a private company belonging to Colonel David Stirling , founder of the Special Air Service ( SAS ) , who recruited dozens of former SAS men as advisors to the royalists . Britain participated in a $ 400 million British air defense program for Saudi Arabia . The Lyndon Johnson administration was more willing than Kennedy ' s to support long - range plans in support of the Saudi army . 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 which provided the Saudi forces with combat vehicles , mostly trucks . Faisal also initiated an Islamic alignment called the Islamic Conference , to counter Nasser ' s Arab socialism . The tribes of Southern Saudi Arabia and Northern Yemen were closely linked , and the Saudis enticed thousands of Yemeni workers in Saudi Arabia to assist the royalist cause . In addition to the Saudis and British , the Iraqis also sent plane loads of Baathist Yemenis to undermine Sallal ' s regime . The royalists fought for the Imam despite his father ' s unpopularity . One sheik said " The Imams have ruled us for a thousand years . Some were good and some bad . We killed the bad ones sooner or later , and we prospered under the good ones " . The hill tribes were Shia , like the Imam , while the Yemenis of the coast and the south were Sunni , as were most Egyptians . President Sallal was himself a mountain Shia fighting with lowland Sunnis . Al - Badr himself was convinced that he was Nasser ' s biggest target , saying " Now I ' m getting my reward for befriending Nasser . We were brothers , but when I refused to become his stooge , he used Sallal against me . I will never stop fighting . I will never go into exile . Win or lose , my grave will be here " . Al - Badr had formed two royalist armies — one under his uncle Prince Hassan in the east and one under his own control in the west . Both armies controlled most of the north and east of Yemen , including the towns of Harib and Marib . The provincial capital of Northern Yemen , Sadah , which would have given the Imam a key strategic road towards the main capital San ' a , was controlled by the republicans . There were also areas like the town of Hajjah , where the royalists controlled the mountains while the Egyptians and republicans controlled the town and fortress . 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 . They trained tribesmen in the use of antitank weapons , such as the 106mm gun and in mining techniques . The numbers of mercenaries are estimated in the hundreds , although Egyptian sources at the time reported 15 , 000 . Royalist tactics were confined to guerilla warfare , isolating conventional Egyptian and republican forces , and conducting attacks on supply lines . British involvement 1962 - 1965 . According to Duff Hart - Davis , the British mercenary leader Jim Johnson had originally considered buying their own aircraft , a Lockheed Constellation 749 . He then flew to Teheran to try to persuade the Iranians to do an air drop . 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 . Hart - Davis confirms that Tony Boyle , a former RAF pilot and Jim Johnson ' s second in command , was on board the first flight , but as an observer , and describes the rest of the staffing as entirely Israeli , with " some 200 people involved " , including not only the " Stratocruiser " crew but marine rescue and helicopter crews in case of sea or land rescue , an Israeli army " insertion unit " , and Meir Amit . The plane was flown by Israeli Air Force transport pilot Major Arieh Oz . The first weapons drop , witnessed on the ground by British mercenary Lieutenant Colonel Johnny Cooper , provided the royalists with a morale - boosting 180 old rifles , 34 , 000 rounds of Mauser and 17 , 000 rounds of . 303 rifle ammunition , 72 six - pounder antitank shells and 150 pounds of plastic explosive . The Israelis had systematically concealed the source of the weapons , brazing out all the serial numbers , using Italian parachutes , and even ensuring that the packaging consisted of wood - shavings from Cyprus . Three decades after the war , former Mossad director , Shabtai Shavit , and Ariel Sharon both said Israel had been clandestinely involved in Yemen . Some of the royalist air drops were organized by the British using the Israeli Air Force ( IAF ) aircraft , which were contracted privately to the British mercenary operation and were either using Israeli air bases or Israeli transport planes themselves making the drops . According to " Haaretz " newspaper , Tony Boyle 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 . It was decided that the airdrops would be made . The originally Israeli aircraft flew along the Saudi coastline . Haaretz suggested the crew were British ; according to Hart - Davis the crew were Israeli , with Tony Boyle on board as an observer . The Saudis did not have radar systems , and would later claim they were not aware of the airlifts . The planes would make the drops and then refuel in French Somaliland ( now Djibouti ) and return to Israel . The airlifts were originally codenamed " Operation " Gravy " " , but were later renamed " Operation " Porcupine " " . The IAF ' s largest transport plane , a Stratofreighter , was recruited for the British operation . The first flight took off in March 1964 from Tel Nof Airbase . During the sixth flight , Boyle suggested that the IAF aircraft would also be used to bomb San ' a . Weizman supported the idea and plans were made , but the Israel Defense Forces Chief of Staff ( Ramatkal ) Yitzhak Rabin and Israeli Prime Minister , Levi Eshkol , denied him . The " Porcupine " operation went on over a period of slightly more than two years , during which the Stratofreighter carried out 14 nighttime sorties from Tel Nof to Yemen . Mossad operated at least one agent in Yemen , Baruch Mizrahi , who was caught in 1972 and imprisoned in Egypt . He was released in a prisoner exchange between Egypt and Israel following the Yom Kippur War in 1973 . British support remained covert throughout . The Prime Minister Alec Douglas - Home replied to Michael Foot ' s parliamentary question on 14 May 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 . It is not therefore our policy to supply arms to the Royalists in the Yemen , and the Yemen Government have not requested these or other forms of aid . " To a further question ( by George Wigg ) , Douglas - Home said that " at no time in the last eighteen months have British arms been supplied to the Imam ' s Government " . Hart - Davis notes that this " may have been strictly true ; but . . . a great many weapons of non - British provenance had been spirited into the Yemen through Jim Johnson ' s machinations . " British mercenary involvement became public knowledge , when 5 letters addressed to Johnny Cooper were captured by the Egyptians in November 1963 . Their content was published by " Al - Ahram " and then broadcast by Cairo radio on 1 May 1964 . Al - Ahram quoted an estimate for British , French and other foreigners of " over 300 officers " , " directed from Britain and most probably under the command of British Intelligence " . On 5 July 1964 the Sunday Times published the letters , connecting " these Buchan esque freebooters " ( Cooper and his team ) with Tony Boyle . However , the British Government was able to continue denying any knowledge of mercenary activity . On 21 July 1964 , Douglas - Home replied to a parliamentary question by saying " Both the present High Commissioner and his predecessor have assured us that they were not aware that the person in question ( Tony Boyle ) was involved in any way " . The following day ( 22 July 1964 ) , Douglas - Home sent a memorandum to the 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 result was that a secret Joint Action Committee was created to handle British policy on Yemen . Saudi and Jordanian support . Saudis and Jordanians provided an active support to the royalists through the first years of war . At some point Saudi border towns and airfields were attacked by Egyptian forces in order to " prevent Saudi supplies and ammunition from reaching Royalist - held areas in the Yemen " . Egyptian deployment . 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 . A little less than 5 , 000 troops were sent in October 1962 . Two months later , Egypt had 15 , 000 regular troops deployed . By late 1963 , the number was increased to 36 , 000 ; and in late 1964 , the number rose to 50 , 000 Egyptian troops in Yemen . In late 1965 , the Egyptian troop commitment in Yemen was at 55 , 000 troops , which were broken into 13 infantry regiments of one artillery division , one tank division and several Special Forces as well as paratroop regiments . Ahmed Abu - Zeid , who served as Egypt ' s ambassador to royalist Yemen from 1957 to 1961 , sent numerous reports on Yemen that did not reach Ministry of Defense officials . He warned Egyptian officials in Cairo , including Defense Minister Amer , that the tribes were difficult and had no sense of loyalty or nationhood . He opposed sending Egyptian combat forces and , arguing that only money and equipment be sent to the Yemeni Free Officers , and warned that the Saudis would finance the royalists . All the Egyptian field commanders complained of a total lack of topographical map s causing a real problem in the first months of the war . Commanders had difficulty planning military operations effectively or sending back routine and casualty reports without accurate coordinates . Field units were given maps that were only of use for aerial navigation . Chief of Egyptian Intelligence , Salah Nasr , admitted that information on Yemen was nonexistent . Egypt had not had an embassy in Yemen since 1961 ; therefore when Cairo requested information from the US ambassador to Yemen , all he provided was an economic report on the country . In 1963 and 1964 the Egyptians had five squadrons of aircraft in Yemen at airfields near San ' a and Hodeida . They were using Yak - 11 piston - engined fighters , MiG - 15 and MiG - 17 jet fighters , Ilyushin Il - 28 twin - engined bombers , Ilyushin Il - 14 twin - engined transports and Mil Mi - 4 transport helicopters . They were also flying four - engined Tupolev bombers from bases in Egypt , such as Aswan . All the air crew were Egyptian , except for the Tupolev bombers which were thought to have mixed Egyptian and Russian personnel . The Ilyushin transports flying between Egypt and Hodeida had Russian crews . Throughout the war , the Egyptians relied on airlift . In January 1964 , when royalist forces placed San ' a under siege , Egyptian Antonov heavy - lift cargo planes airlifted tons of food and kerosene into the region . The Egyptians estimate that hundreds of millions of dollars were spent to equip Egyptian and republican Yemeni forces , and in addition , Moscow refurbished the Al - Rawda Airfield outside San ' a . The politburo saw a chance to gain a toehold on the Arabian Peninsula and accepted hundreds of Egyptian officers to be trained as pilots for service in the Yemen War . Egyptian air and naval forces began bombing and shelling raids in the Saudi southwestern city of Najran and the coastal town of Jizan , which were staging points for royalist forces . In response , the Saudis purchased a British Thunderbird air defense system and developed their airfield in Khamis Mushayt . Riyadh also attempted to convince Washington to respond on its behalf . President Kennedy sent only a wing of jet fighters and bombers to Dhahran Airbase , demonstrating to Nasser the seriousness of American commitment to defending U . S . interests in Saudi Arabia . Peace attempts : Khamir , Jeddah and Haradh conferences . Khamir . Noman spoke over Radio San ' a , offering reconciliation and inviting " all tribes of all persuasions " to meet with him the following week at Khamir , 50 miles north of San ' a , to achieve " the one thing which we all prize over anything else : peace for the nation . " In order to convince al - Badr to come the conference , Noman announced that he personally would head the republican delegation at Khamir , and that Sallal would stay in San ' a . Al - Badr and his ranking chiefs did not attend the conference , but a handful of pro - royalist sheiks were present . The conference named a committee of five tribal and four religious leaders who were charged with seeking out the " beguiled brothers " , al - Badr and his friends . Noman ' s effort , including a private promise to reach a withdrawal of Egyptian troops , was backed by Nasser . Radio Cairo hailed the Khamir conference as the " dawn of a new era . " 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 . " However , by early June , when Noman said that Egypt ' s 50 , 000 troops would have to be replaced by a joint royalist - republican peace force , the Nasserites lost interest in the deal . After Noman flew to Cairo to protest directly to Nasser , Sallal threw seven civilian Cabinet ministers into jail . Noman resigned , saying " It is obvious that Sallal and his cronies are more interested in war than peace " . Sallal soon named a new Cabinet to replace Noman ' s , with 13 military men and two civilians . Jeddah . By August , the war was costing Nasser $ 1 , 000 , 000 a day , when he arrived in Jedda harbor aboard his presidential yacht Hurriah ( Freedom ) to negotiate with Faisal . It was Nasser ' s first visit to Saudi Arabia since 1956 . At the request of the Egyptians , due to assassination rumors , the banners and flags normally put up to celebrate a visiting dignitary were omitted , the sidewalks were cleared of people , and the car was a special bulletproof model . On the evening of his arrival , Nasser was welcomed at a banquet and reception for 700 guests . In less than 48 hours they reached full agreement . Once the agreement was signed , Faisal embraced Nasser and kissed him on both cheeks . The agreement provided for Haradh . On November 23 , the two sides met in Haradh . The first issue was the name of the transition state that was supposed to exist until a plebiscite could be held the following year . The royalists wanted the name " Kingdom of Yemen " but were willing to settle for a neutral title like " State of Yemen " . The republicans insisted on having the word " republic " or " republican " in the title . It was agreed to suspend the conference until after the month - long fast of Ramadan , which was about to begin the following week . The conference reached a deadlock when the Egyptians , possibly due to a tactical decision made by Amer , encouraged the republicans to take a headstrong stand .