In the preface to “Cambodia’s Curse: The Modern History of a Troubled Land,” Joel Brink­ley recalls his first encounter with Cambodia. Brinkley was reporting for The Louisville Courier-Journal from a refugee camp near the Thai border in 1979, in the aftermath of Pol Pot’s reign. “As they tell of years of horror and misery,” Brinkley wrote, “their faces are expressionless and dull . . . as if they’re talking about a dull day of work. Their tales end with a nodding acknowledgment of the death of their nation and culture.” Brinkley, who later worked for The New York Times, finds little has changed in the 32 years since then. As the title suggests, his book is an unabashed plea to refocus international aid and diplomacy on a suffering people. It is also an attempt to hold some of those responsible for that suffering accountable — but not all.Cambodia lost a quarter of its population under the Khmer Rouge. For many, survival meant 14-hour days of backbreaking work, often on little more than a cupful of rice or a smattering of gruel. You could be killed on the least suspicion you sympathized with the Vietnamese. The effects of this period have proven hard to shake.