Cut the domain

Where did Kangxi's confidence to cut the domain come from, do you know that Wu Sangui has laid half of the country?
Wu Sangui Kangxi Cut the domain Qing Dynasty San Francisco The San Francisco Rebellion
12-17
Why did Wu Sangui choose to rebel and not want to be a rich man?
Wu Sangui Kangxi Cut the domain Ming dynasty Li Zicheng Yongli Emperor
12-16
Tang Dezong's slashing of the domain almost led to the fall of the country, why did he use only one edict to defuse the crisis?
Tang Dezong Tang dynasty Cut the domain Sin yourself Li Xilie
12-16