From Arabian Assignment: Operations in Oman and the Yemen, by David Smiley. (The Extraordinary Life of Colonel David Smiley Book 2; Sapere Books, 2020), Kindle pp. 234-235:
When I reached Jedda early in March, 1966, the Egyptians had already broken the ceasefire and resumed bombing in all areas of Royalist Yemen. For a brief period after the Haradh Conference President Nasser seemed to lose heart, and began withdrawing troops from the country; from its peak of 70,000 their number dropped to about 20,000 at the beginning of February. At that moment the British Government issued their notorious Defence White Paper, announcing our withdrawal from the Persian Gulf, and the situation changed overnight. Nasser saw a fresh opportunity to seize Aden, and began to reinforce in the Yemen until he had nearly 60,000 troops there. More important, the White Paper marked the final eclipse of British prestige among the Arabs. Only two weeks previously Goronwy Roberts, Minister of State at the Foreign Office, had toured the Gulf and given the Rulers positive assurances that the British would stay. Hitherto the Arabs had trusted the British, despite many disappointments, to the extent that the phrase ‘word of an Englishman’ had become a part of their vocabulary; after the White Paper it ceased to have any meaning.