Campaigners have called on the US to cancel millions of dollars of outstanding debts owed by Cambodia - money that was given to the country when it was a part of Washington's Cold War alliance in south-east Asia.
Secretary of State Hilary Clinton and Cambodian officials this week agreed to continue negotiations over $445m accumulated by the US-backed regime of Gen Lon Nol in the early 1970s. The regime was eventually ousted by the Khmer Rouge and its senior officials and US advisers were forced to flee the country.
Mrs Clinton suggested the current Cambodian government could repay some of the debt while a portion of it could be "swapped" for investment in education or the environment."There are things that the government of Cambodia could do that would satisfy the need to demonstrate some level of accountability but, more importantly, to invest those funds in the needs of the people of Cambodia," she told Cambodian students while on a seven-nation tour of Asia.
But campaigners say the US should write off the money. Nick Dearden, head of the advocacy group Jubilee Debt Campaign, said: "We think there is no question - it should be written off. We see no reason why Cambodia should be repaying debts that should never have been leant in the first place and which were only leant for the benefit of the lender."
He added: "Also, it's in no place to repay the debt. Cambodia is a very poor country and simply to try and meet its Millennium Development goals and to grow, it is in no position to pay off this money."
The money was given to the regime of Lon Nol as the US sought to stop the advance of both the Khmer Rouge rebels in Cambodia and the forces of North Vietnam in Vietnam. In both cases if failed, while its massive military operation in south-east Asia, including a secret bombing campaign in Cambodia, left hundreds of thousands dead and maimed. Cambodia and Laos were among the most heavily bombed nations on the planet.
"In 1970-1975, the Khmer Republic as it was then known, was a client state of the United States," said David Chandler, an expert on Cambodian history.
"Gen Lon Nol, who had overthrown [the government of Prince] Sihanouk, was pro-US and anti-Vietnamese, and the US used him to draw Vietnamese troops into Cambodia so as to ease the US withdrawal from Vietnam."
Analysts say there is little prospect of the money being repaid to the US by the current Cambodian government, headed by Prime Minister Hun Sun. Rather, Mrs Clinton may have raised the issue as part of a process of greater leverage as it tries to counter growing Chinese influence there.
Indeed, asked about the role of China, which has invested heavily in Cambodia and provided millions of dollars in aid as the Phnom Penh government seeks to rebuild the country after years of war and turmoil, she said: "You don't want to get too dependent on any one country. There are important issues that Cambodia must raise with China."
Mrs Clinton also visited the Tuol Sleng jail, where more than 14,000 prisoners were questioned and tortured by the Khmer Rouge before being dispatched for execution at killing fields on the edge of the city.
Earlier this year, the prison chief, Kaing Guek Eav, also known as Comrade Duch, was sentenced to 19 years in jail at the conclusion of the first trial completed by the UN-sponsored tribunal.
A second trial involving four other senior leaders is due follow soon. Prime minister Hun Sen has said he will not tolerate further trials as it could damage the fabric of the country but Mrs Clinton, who said her visit to Tuol Sleng had been a "very disturbing experience", said the tribunals were crucial.
"Countries that are held prisoner to their past can never break those chains and build the kind of future that their children deserve," she added. "Although I am well aware the work of the tribunal is painful, it is necessary to ensure a lasting peace."