The treason trial of Cambodian opposition leader Kem Sokha opened Wednesday, more than two years after his arrest in a case decried by his family as a "farce" and widely pilloried as politically motivated.The 66-year-old co-founded the now-banned Cambodia National Rescue Party, once considered the sole viable opponent to the ruling Cambodian People's Party (CPP) led by strongman premier Hun Sen - who has ruled the country with an iron fist for 35 years.Sokha was arrested in 201