1, Cixi did declare war in the name of Guangxu, but the declaration did not say who to declare war on.
2. Guangxu appointed Kang Youwei and Liang Qichao to carry out political reform, thus opposing conservatives. Cixi wanted to depose Guangxu, but she was afraid to act because of opposition from all countries, and she held a grudge against it. In addition, foreign powers tried to carve up China, renting harbors in succession and dividing their spheres of influence, which also increased Cixi's xenophobia.
3. Cixi trusted the ignorant conservative ministers and listened to Yuxian's words. She believed that members of the group could be "invulnerable" and "invulnerable" and encouraged Cixi to use the Boxer Movement to exclude foreigners. Therefore, the Boxer Rebellion entered the palace in Beijing under the slogan of "helping the Qing Dynasty to destroy the foreign countries". Boxers killed foreigners and Christians everywhere, burned churches, tore down power lines, destroyed railways and occupied Tianjin Concession. Countries asked the Qing court to ban the Boxer Rebellion, but there was no response.
The above gave excuses and reasons for the western powers to invade China, so the eight countries successively sent military towns to suppress the Boxer Rebellion, but it was actually a war of aggression against China.