Iraq's unruly century: ever since Britain carved the nation out of the Ottoman Empire after World War I, the land long known as Mesopotamia has been wracked by instability.

As summer temperatures headed toward 105 degrees on the morning of August 23, 1921, some 1,500 dignitaries assembled in the courtyard of a government building on the banks of the Tigris River for a coronation. British Army officers and colonial administrators mingled with Shiite Arabs from Basra near the Persian Gulf, Kurds from Mosul near Turkey, and Sunni Arabs from Baghdad to witness the installation of a foreign prince, Faisal, as the first king of the newly created nation. "It was an amazing thing to see all Iraq, from North to South, gathered together," wrote Gertrude Bell, a British colonial official who had recommended Faisal to her government and would be his staunchest supporter. "It is the first time it has happened in history."

Faisal's subjects had no anthem, so a band struck up "God Save the King." The selection aptly symbolized Britain's role not only in inventing the Iraqi government--complete with a figurehead king and soon a new parliament and constitution--but also in orchestrating it for years to come.

On a July morning in Baghdad in 1958, Iraq's constitutional monarchy came to a brutal end when an army faction led by Iraqi Gen. Abdul Karim Qassem stormed the royal palace. In the courtyard, rebel troops killed King Faisal II, the 23-year-old grandson of the first monarch, and a score of men, women and children. Faisal's body was removed to a secret burial place. But no such respect was accorded his uncle and former regent, Abdul Ilah, whom the plotters blamed for the monarchy's pro-British slant; his corpse was thrown to a mob outside the palace gates, dragged around the city and displayed for two days in a public square.

The 1958 coup d'etat was not the first upheaval in Iraq's modern political history, which has been marked by nationalist fervor, ethnic uprisings, tribal conflicts, palace treacheries, warfare and deadly oppression. In the monarchy's 37 years, the government cabinet was shuffled more than 50 times. Scholars have offered a catalog of reasons why antiquity's "cradle of civilization" has been so unstable. Some blame geography, pointing out that Iraq, which covers some 168,000 square miles, has a mere 12 miles of shoreline, on the Persian Gulf, making it the most landlocked--and culturally isolated--nation in the Middle East. Others tie Iraq's "bloody history," as many have described it, to the preponderance of groups vying for power. The rivalry goes deeper than Arab versus British, however, or Sunni versus Shiite versus Kurd. As the Kurdish analyst Siyamend Othman said this past November, the "history of Iraq has been conditioned, if not determined, by the conflict between city and countryside," meaning the conflict between an emerging educated class around major urban areas and the old semiliterate rural sheikhdoms.

Britain's experiment in nation-building failed partly because it did not unify the disparate factions, says Charles Tripp, a British citizen and author of the 2000 book, A History of Iraq. Instead, Britain seeded unrest by relying on the Sunni minority to run the military and civil service and also by subordinating the northern, Kurdish territory. In addition, he says, Britain's decision to allow tribal sheikhs to maintain order in rural areas heightened tensions by "treating Iraqi society as a collection of groups rather than individuals."

But Adeed Dawisha, an Iraq-born historian and author of Arab Nationalism in the Twentieth Century, suggests that Britain failed mainly because it granted Iraq too little autonomy. "From the establishment of the constitutional …