In the middle of the 19th century, Ireland was beset by two great tragedies: One was a natural disaster of epic proportions; the other was entirely man-made.

In 1845, a fungus struck potato crops in northern France, crossed the channel to the British Isles and eventually spread through northern Europe. Ireland was particularly vulnerable. A large part of the Irish population — two-thirds or more — relied on subsistence farming. Potatoes were the crop that did best, well adapted to the harsh weather and growing conditions in a country full of small farms. The poorest people could live on a diet largely of potatoes which were rich in Vitamin C and readily supplemented by herbs, other vegetables and bits of snare-caught meat.

But the Irish potato crop failed three relentless years in a row. Malnutrition set in, starvation followed, then diseases swelled to plague proportions. A million Irish died and two million more fled the country, some leaving their children behind. Mass death and emigration would reduce Ireland’s population by a third, nearly beggaring its future. It was one of the great disasters of the age.

All of the British Isles were under one London-based government, and for ages tradition had been to look down on the Irish. Ireland lacked good harbors; its weather was unforgiving; much of its population was poor and seemingly rooted in medieval times and cultures. One influential British official concluded, “Providence never intended Ireland to be a great nation.”

Such were the underpinnings of Ireland’s second great tragedy: the inept, grotesquely inadequate, stunningly misguided and palpably inhumane relief policies and programs of the British government.

Author John Kelly has written 10 books on topics of science, history and human behavior, including his highly regarded The Great Mortality: An Intimate History of the Black Death. In The Graves Are Walking, Kelly proves himself astute in political analysis, as well.

As Kelly puts it, British public officials were politically unable to deal with the problems rationally and thereby “turned a natural disaster into a human disaster.” As famine and pestilence spread and multiplied, the dimensions of the disaster were misidentified and debated and denied and reconsidered by one high public official and committee after another. Procuring alternative food supplies when much of Europe was also vying for them, and then trying to arrange for storage and delivery, required  organizational skills and supply lines that were nearly non-existent, as well as huge and ever-increasing amounts of money. Workhouses and public works programs could not accommodate so many people desperate to survive. A senior military officer recruited to ramp up food relief efforts called a halt to the program until he could design and perfect a system of his own, insisting that “a sound infrastructure be in place before serving a single bowl of soup.” And so it went.

Political factors undermined even the better plans and processes, exacerbating the destitution, famine, plagues and mass death. Key public officials were in thrall of the “Moralist” fervor of the era, “an evangelical sect that preached a passionate gospel of self-help” and, according to Kelly, opposed public assistance believing that it undercut self-reliance, discipline, industriousness and sobriety. The Moralists looked down on the Irish and perceived their growing “dependence on government” as the overriding problem. Simply put, the Irish were suffering God’s judgment and there were limits on how much they could be helped. Newspapers across England echoed these sentiments.

Economic policy was another cruel political failure. Throughout England, contention had been growing for decades between industrialists and landowners (including the Irish gentry) on one side and peasant farmers and laborers on the other. High tariffs kept foreign imports at bay, raising profits to the investors and increasing prices to consumers. The Irish famine predicament presented an ideal opportunity to impose modernized agricultural processes, to marshal a subsistence labor force to work instead on larger and more productive farms, farms that could raise beef cattle and grain crops, thereby to yield higher returns than potatoes.

Ireland was a country crisscrossed by one, five and 10-acre plots, properties that were not amenable to the large-scale operations required for agricultural modernization. In 1847, Parliament extended its Poor Laws by enacting a stunningly perverse policy. In this, the third year of the famine, the British government promised meager food rations and possible employment to those farmers who still survived, starving and near death — but only on the condition that they give up all but a quarter-acre of their land.

John Kelly concludes, “If the famine has any enduring lesson to teach, 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.”

This fine book is sourced largely from contemporaneous accounts and is thoroughly documented. It is a witheringly bleak portrayal, extraordinarily detailed and gracefully written. Everyone who holds a policy-making position in government today or tomorrow should study this book.

Like all good histories, it is a cautionary tale.

Tom Phillips is a retired corporate attorney who lives in Chicago and grumbles a lot about national politics and mankind.