In June 1845, potato farmers in Flanders, Belgium, noticed a putrid stench in the air. They discovered that their potato plants, luxuriantly green only days before, were now wilted and black, the potatoes in the earth not just stunted, but rotten, oozing a horrid red-brown mucus.

By the end of July the blight had spread across the continent. In August it invaded the Channel Islands and finally, devastatingly, Ireland. In Northern Europe, the blight caused severe hardship; in Ireland, where two-thirds of the population subsisted upon the potato, it led to catastrophe. Ten years after the famine began, one-third of Ireland's population (8.2 million in 1845) had been erased, with 1.1 million dead and 2 million emigrated.

Other famines had occurred in modern Europe, but their effects did not decimate a population. What set this one apart? Simple bad timing played a role, John Kelly tells us: Had the blight occurred earlier, when Ireland was less dependent on the potato, or later, when the economy was stronger, the effects might have been more confined; in the 1840s, the Irish infrastructure was too primitive, the poverty too severe, to avert widespread starvation or provide relief. But, Kelly argues, timing alone cannot account for the huge losses. "What turned a natural disaster into a human disaster was the determination of senior British officials to use relief policy as an instrument of nation building."

The English applied the metrics of modernism to Ireland and found it wanting, particularly in terms of agriculture (too many small farms) and "character." (The Irish showed a regrettable "dependency on government" as well as a work ethic defined "by ancient Celtic rhythms.") For British policymakers, the famine offered an opportunity to modernize Irish agriculture and Anglicize the Irish character. The resulting relief program, "more concerned with fostering change than with saving lives," was "parsimonious, short-sighted, grotesquely twisted by religion and ideology," producing "tens of thousands, perhaps hundreds of thousands of needless deaths."

"The Graves Are Walking" is meticulously, though unobtrusively, documented as Kelly moves with novelistic verve between the micro and the macro; lucid explications of political and economic policies are seamlessly integrated with profiles of the policymakers. By including narratives of famine victims, Kelly creates a visceral understanding of the unbridgeable gulf -- economic, ideological and cultural -- that enables the officials' utter failure of empathy. Although famine-era English officials have been portrayed as "genocidal gargoyles," the truth, Kelly argues, is even more depressing: They were generally "wakeful minded, God-fearing, and ... well intentioned men." But while "the intent of [their] policies may not have been genocidal, the effects were."

If the famine has any enduring lesson, "it is about the harm that even the best are capable of when they lose their way and allow religion and political ideology to traduce reason and humanity."

Patricia Hagen teaches English at the College of St. Scholastica in Duluth.