Fourteen months ago, as ordinary Syrians were just beginning to gather in large numbers to call for their leaders to quit power, a cherub-faced 13-year-old named Hamza Ali al-Khateeb was taken into custody after he’d been caught scrawling an antigovernment slogan on a wall at a protest in the town of Jiza. A month later, when Hamza’s body was returned to his parents, it bore signs of the most hideous torture. His face had been beaten purple, his jaw and kneecaps pulverized, his body stabbed and torched. His penis had been chopped off.

There was a time, and not so long ago, when a Syrian dictator could plausibly assume that such a demonstration of official sadism would silence any popular murmurings for a more democratic form of governance. Brutality always worked before. But by April 2011, the Middle East had changed — Syrians had changed, even if the regime of Bashar al-Assad had not. The mutilation of young Hamza did not crush the Syrians; it enraged and catalyzed them. The result, little more than a year later, is an epic struggle that horrifies and inspires. It’s hard to imagine that the dictator and his confederates can hang on, but still they do.

In “The Syrian Rebellion,” the Middle East scholar Fouad Ajami weaves the threads of Syria’s past with the events of the previous year to give us a portrait of the country as it hurtles toward its moment of decisive transformation. This is no small feat: Syria is a country of enormous ethnic and religious complexity, and the story is moving very fast. “The Syrian Rebellion” is an elegant and edifying book, written on the fly, by an observer who retains an almost loving intimacy with his subject. But it is underlain by a sobering subtext: Ajami suggests that the dynamics of Syria’s politics and history are leading inexorably toward a catastrophe, or at least no quick and happy end. If he’s right, we have probably not yet seen the worst.

Syria is another of the improbable constructions that arose from the ruins of the Ottoman Empire after World War I. The new country was a grab bag of ethnicities and religions, conjured up by colonial mapmakers with little regard for either. In Syria, the dominant group is not the Sunni Arabs, who make up the overwhelming majority; nor even the Christians, a significant minority; but the Alawites, a heterodox Shiite sect that constitutes 12 percent of the population. A largely rural people at the time of Syria’s birth, the Alawites came to dominate first the military and then the country itself. Their ascent was aided by the French, who ruled until the 1940s, and who, in the way of the colonial master, maintained a policy of favoring minorities at the expense of the Sunnis. Hafez al-Assad, a steely-eyed air force officer, secured his hold on power in the 1970s, using the secular-minded Baath Party as his vehicle (its sister party, eventually led by Saddam Hussein, lay across the border in Iraq). When Hafez died, in 2000, he bequeathed power to his son, the London-educated Bashar, age 34.