Chiang had to defeat three separate warlords and two independent armies. Estrada arrested criminal warlords and kidnapping syndicates. The opium trade spiked in 2006 after the Taliban lost control of local warlords. Hunan Province was ruled by successive autonomous warlords. Zhang Guotao's forces were soundly defeated by the local Nationalist warlords, the Ma clique. The Red Army had to capture river crossings defended by warlords and Nationalist troops. Chiang preferred to unite China by eliminating the warlords and CPC forces first. The Han empire was divided between a number of regional warlords. Various subsects of Buddhism emerged that were patronized by the various Mongol warlords. Trade and political accords between the warlords deteriorated. The government was seeking to exert full control over frontier areas against the warlords. The Chinese government sought to exercise full control over frontier areas against the warlords. Guizhou Province was dominated by a series of successive autonomous warlords. Emperor Xian fell into the hands of various warlords in Chang'an. Few of the warlords had any sort of ideology.