Three days into my first visit to the United Arab Emirates, I was standing near a date market with my husband, who was fidgeting with a vending machine, trying to buy a bottle of water. He hadn’t the right coins for the machine. Suddenly a car pulled up onto the kerb, and out of it jumped a woman, offering coins. My husband demurred. “Oh no, I couldn’t possibly …” Elbowing him sharply in the “keep your mouth shut” code he had learned over 20 years of marriage, I accepted the coins and bought a bottle of water. I was thinking back to 20 years before when I had been lucky enough to meet the writer-explorer Wilfred Thesiger, then elderly and almost blind. In his book Arabian Sands, about exploring the wildest and most unknown areas of the Arab penin