The question of the Saudi Arabia-Abu Dhabi frontier, what one British diplomat called the ‘Schleswig/Holstein problem of our times’, was still unsettled at the time of the British withdrawal from the Gulf, when King Faisal had made it clear that while his territorial demands on Abu Dhabi remained unsatisfied he would not recognise the existence or legitimacy of the UAE. Occasional exchanges over the issue took place between Faisal and Zayid, often using intermediaries, between 1972 and 1974, and then on 21 August of that year an agreement was reached between them. Zayid gave the Saudis nearly everything they had demanded – a corridor to the sea, west of the Sabkhat Matti, thus separating Qatar from Abu Dhabi and giving Saudi Arabia an outlet to the lower Gulf; a major slice of the western part of Abu Dhabi, and now the UAE, which included the Phillips Petroleum field; and in the south, all the oil and gas located in the Shaiba-Zarrara field, including that part of the structure on the UAE side of the border and that located in the angle formed by the Umm al-Zamul dogleg frontier with Oman. It was clear that the Saudis were after as much oil as they could get (see Appendix 8 and map 40). By surrendering to the Saudis in this way, Zayid in effect handed over to them the concessionary rights he had awarded earlier to foreign oil companies in the ceded territories, including ADPC's rights to the Zarrara field, of which only a small portion was left in the company's concessionary area. In return for these concessions by Zayid, Faisal recognised the UAE and it was presumed by Zayid that Faisal had withdrawn the Saudi claim to the Buraimi oasis and the corridor of territory leading to it. This claim was, of course, as unwarranted as Faisal's claim to the western and southern areas of Abu Dhabi which Zayid had conceded. Despite the sense of elation in Riyad and Abu Dhabi that the frontier dispute had been finally resolved, on which they were congratulated by the British government, there was some doubt in London about certain aspects of the agreement. With regard to the Saudi corridor to the Gulf, the new border between Saudi Arabia and the UAE crossed the shore line at the eastern end of the Khaur al Dhuwayhin. The continuation of that line offshore placed Huwaysat Island within Saudi waters (under Article 5). An exchange of letters between Faisal and Zayid of the same date as the agreement (21 August 1974) stated that there was ‘joint sovereignty over the entire area linking the territorial waters of the Kingdom of Saudi Arabia and the high seas…’