Cambodia should be viewed through the lens of the Khmer Rouge (Cambodian Communist) regime led by Pol Pot, 1975-79. An estimated two to three million people (about a quarter of the population) were killed, the currency eradicated, religion outlawed, hospitals shuttered, and schools closed, setting the country back hundreds of years. Genocide targets included professionals, intellectuals, artists, foreigners, diplomats, and any other suspected political enemies. A slower death faced urbanites who were forced out of the cities and onto collective farms. Cambodia has managed an incredible recovery in only 40 years, yet the after-affects are still visible, and it is considered an LDC (least developed country). Currently described as a constitutional monarchy, it has a single party and the second-longest serving prime minister in the world, so you can drawn your own conclusions.
Phnom Penh to Kampong Thom, 20 flat miles, overcast with occasional light rain, mid-80s Kampong Thom to Siem Reap, 40 flat and fast miles, partly cloudy, mid-80s