 Complete the following phrase:  Cẩns influence began to wane after his elder brother Ngô Đình Thục was appointed the Roman Catholic Archbishop of Huế. Thục overshadowed Cẩn and aggressively promoted Catholicism, which led to the banning of the Buddhist flag in 1963 during Vesak, the celebration of the birthday of Gautama Buddha. Cẩns forces opened fire on a crowd who were protesting the ban, killing nine and precipitating the Buddhist crisis. Ongoing demonstrations intensified throughout the summer as the regime responded with increased brutality, sparking the toppling of the Diem regime in a 