On 14 November 2024, in the Isara Vinijchai Throne Hall of the Bangkok National Museum, the Representatives of the US Government officially returned several precious Ban Chiang artefacts to the Government of Thailand. It was the result of years of negotiations. This ceremony followed other similar successful cases, the most famous being the Phra Narai lintel of Phnom Rung, returned by the USA to Thailand in 1988. As to Cambodia, since 1995 it has developed a systematic policy of requesting the return of ancient statues and bronzes stolen in the 70s and 80s, now disseminated all over the world among museums, galleries and private collections. In some instances, discussions have been ongoing for decades with less success, exemplified by Greece requesting the return of the famous Parthenon Marbles on display at the British Museum for more than 200 years. What are the motivations of countries which engage in such difficult and sometimes costly negotiations, with no guarantee of success? What are the arguments raised? Two visions are opposing. On the one hand, those for whom these works of art have entered the heritage of the former colonial powers, and it is unthinkable to return them, especially when they are currently under the best possible condition of conservation. On the other hand, those who would find it fair and equitable to proceed, in whole or in part, to the return of cultural objects which have a particular significance for the people of their country of origin. Etienne Clément, who has been in charge of this dossier at UNESCO, will speak on this thorny subject by providing some background to the topic and sharing some of his thoughts.