The Americans were blamed
for the rise of Pol Pot in Cambodia and for funding his army

Blamed by who? No sane individual.

From 1969-1973 the United States secretly dropped upwards of 2.7 million tons of bombs on Cambodia, exceeding the amount it had dropped on Japan during WWII (including Hiroshima and Nagasaki) by almost a million tons.

French colonization and its puppet Cambodian monarchy was the fuel for Pol Po (and Ho Chi Minh). Communism was merely a funding and organizing apparatus for his 'freedom fighters'. The genocide in Cambodia was ethnic, not political.

U.S. chemical carpet bombing was non-denominational and supplied by Dow Chemical et al.