Though we continue to live with certain choices of the British Empire, and pay a recurrently heavy price for them, the world will surely never look again with the same wonder and hopelessness upon the likes of those late-19th and early-20th-century officials. Whether in Africa, India, or the Middle East, the British mode of operation grew out of the highest, even noblest, sentiment combined often with the most arrogantly ill-considered policy. Nowhere was this more the case than in their dealings with those desert sheikdoms given over to their jurisdiction by the defeat of the Ottoman Empire.

This is the part of the story that Georgina Howell does not seem to know she is telling in “Gertrude Bell: Queen of the Desert, Shaper of Nations” (Farrar, Straus and Giroux; 419 pages; $27.50). Gertrude Bell, who was born in the Midlands in 1868, a well-set-up Victorian girl slated for a fully proper life, turned out to be as gifted as she was fearless. After writing highly respected works in the field of Middle Eastern archaeology, translating Arabic poetry, traveling among the hostile tribes of the Middle East, and serving as a highly valued adviser on Arab affairs, especially Iraqi affairs, to her government — Bell was finally to become a celebrated citizen of Baghdad, where she spent a good deal of time being ill and died of exhaustion (some say suicide) in 1926.

While Ms. Howell has laid out all of the above in carefully documented detail, the true significance of Gertrude Bell’s life was not, as the author so lovingly tells it, that she was a brilliant and accomplished and unbelievably daring and altogether fascinating woman — though she was without question all of that. The main reason for reviving her memory, however, is something of which the book merely reminds us in a rather uncomprehending manner. Perhaps this is because until now Ms. Howell’s area of concentration has been fashion, a field that concerns itself trustingly with what can be seen and has little to do with what might be lurking, culturally, socially, and psychologically, underneath. (Indeed, there is only one poart of Bell’s career about which Ms. Howell achieves any critical distance, and that is her subject’s opposition to women’s suffrage. At one point, to the biographer’s sharply expressed horror, she actually became the honorary president of an anti-suffrage society.)

Romantic figure as she undeniably was, it is Bell’s all too unromantic service to her government during and after World War I that keeps her on the public books. This phase of her career began in 1915, when she was sent to Cairo to serve as an adviser in the Arab Bureau. The war in Europe was going very badly for Britain, which made it more urgent to foment a rebellion among the Arabs that could assist in bringing about the downfall of the Ottoman Empire. Bell’s knowledge of the sheikhs and tribes would prove to be valuable, most particularly in the region then called Mesopotamia and later, Iraq. By 1920, while the Allies were arranging the peace, she lived in Iraq and busily managed the tribal and ethnic organization of the country, placing her good friend and candidate to be king, Faisal Ibn Saud, on the throne.

The Iraq that followed — not hers alone, but hers emphatically, to be sure — was in certain crucial respects the Iraq that would be found by the U.S. Army in 2003: a Shiite majority in the south, kept from power to avoid an Islamic theocracy, with Sunni and Kurd minorities in the center and north, and a Sunni minority in control of the government. In short, a perfect recipe for bloody murder, and bloody murder there was. Certainly not the only such recipe, not even the most murderous one, to have grown out of World War I. But the faith that Britain would somehow maintain a presence in the region and exercise a benign mandate (the only circumstance that might have given reassurance to someone allegedly as knowing about the Arabs as Gertrude Bell) was not only blind but — the word cannot be denied — positively girlish.

The same applies to her romantic tolerance for the violence of 20th-century Arab life, along with her so-well-bred failure during her visits to the Holy Land to attribute any significance to the bunch of wild-eyed and desperately brave Jews who were settling what they had for millennia known to be their land. It was not her doing, nor exactly was it her fault, that these determined Jews would, without her sympathy or blessing, be thriving long after Britannia had ceased to rule the waves.

Ms. Decter’s most recent book is “Rumsfeld: A Personal Portrait.”