World leaders, including Donald Trump and Jill Biden, are set to attend the inauguration of Notre-Dame Cathedral on December 7 and 8, following its restoration after the devastating fire in 2019. The ceremony, attended by various dignitaries, will feature a mass and a concert with prominent artists. Some notable absences include Pope Francis and Brazilian President Luiz Inácio Lula da Silva. The event is being described as a diplomatic showcase, emphasizing the significance of the cathedral as a symbol of French heritage and European civilization.