Slavery obsesses this desert nation. In parliament, in mosques, lying in tents sipping sweet, green tea, people discuss - and often argue - over whether the Haratin, meaning "former slaves," are in fact free.
Officially, slavery has been illegal in this West African nation almost as long as it has in the United States. Yet many Haratin still provide unpaid services, such as tending livestock and cleaning house. In return, their masters feed and clothe them and are expected to treat them like their own children.
In a society where bartering is still common, is this slavery?
The US Congress says it is. In September, it imposed a ban on all economic and military assistance to the government of Mauritania until the practice is "eliminated." But according to the US State Department and the US Embassy in Mauritania, slavery has "virtually disappeared."
US antislavery lobbyists, many of whom had never been to Mauritania, testified before two congressional subcommittees, telling of Arab slave raids, women and children being sold for about $15 a head, and exotic tortures for disobedient slaves.
Evidence included a receipt for a sale that stated that the buyer "accepts the slave in spite of her insubmissiveness."
But Principal Deputy Assistant Secretary for African Affairs William Twaddel disputed this, and much of the testimony. Embassy staff in Mauritania investigated allegations of the slave sale, he told Congress, and concluded that the signatures on the receipt were forged. And his staff couldn't confirm a single case of "involuntary servitude," he said.
Arab-Berber Maurs enslaved black Africans in the 8th century. But Mohammed ould Hamidy, Mauritania's former representative to the UN and himself a Haratin, claims slavery was never like it was in the US. "Intermarriage [between slaves and other classes] has always been common and acceptable," Mr. Hamidy says. "The enslaved are a class with mobility." His own father was the chief of a powerful Maurish clan.
But other Haratin argue that thousands of their people are not yet free. Messoud ould Boulkheir, head of Action pour le Changement, a political party for the Haratin, says that "many [illiterate slaves] don't even know that slavery has been abolished."
In the "slave section" of Boutilimit, a town in the south-west Sahara desert, Haratin complain that they do not have control over their own lives. Imetha mint Sidaty says her master decided whom she married. Gargayte ould Meyssa says he divorced his wife, a fellow slave, because her master would not let their children go to school. "I did not want to be reproducing slaves," he says.
When Kariya mint Mahomoud's father died, their master inherited everything. Conflict over the inheritance of a slave's property is common, and cases often go before the courts.
Not all Haratin, however, seem oppressed. On Boutilimit's main street, a black man walks hand in hand with an Arab-Berber. Dressed in matching blue tunics, they say they are slave and master as well as best friends.
Some who call themselves slaves admit they have no masters, while others say their masters have little power over them.
Hanna mint Souleymine is one of her master's 25 slaves. But he is destitute, she says, and her family takes care of him.
Increasingly, masters are worse off than their slaves. With recurring drought, many herders have lost their cattle and had to move to the towns with their families and slaves. Urbanization grew from 14 percent in 1970 to 50 percent in 1992, and slaves have often adapted to city life better than their masters.
"Drought and no industry add up to no-wage labor," says Habib Ould Nahfoudh, executive secretary of SOS Esclave, an advocacy group for slaves. "How else are freed slaves and impoverished masters meant to survive?"
Bad economic planning after independence from France in 1960 left Mauritanians among the most indebted people in the world. And while the World Bank says restructuring has been effective in the 1990s, statistics show that the average Mauritanian's purchasing power has declined.
Though the country does not agree on whether real slavery still exists, most Mauritanians admit that some aspects remain.
For Hindou mint Ainina, editor of Le Calame, an independent newspaper, the problem is mostly psychological. "There is the slave mentality and the master mentality. And they both need to change," she says. Although a critic of the government, she does not hold it responsible for slavery. She also questions whether, with US sanctions, the US is pointing its finger at Mauritania or its own past.