While many may not be aware, there is a long historical background behind Cambodian-Vietnamese hostility.

Most Vietnamese in Cambodia cook unhealthy, low quality food. If I see a Vietnamese owns a restaurant, I will avoid visiting that restaurant in the future.
A Cambodian woman voiced that very statement to me, not knowing that I am mixed Vietnamese. Most recently, the hatred for one another was solidified during the Khmer Rouge, a Cambodian Communist genocide in the 1970s. Vietnam supported anti-Phnom Penh sentiments, resolving to invade Cambodia to end the Khmer Rouge regime. As a result, the People’s Republic of Kampuchea (Khmer Rouge forces) taught their military to kill all Vietnamese, seeing them as enemies that must be eliminated at all costs. This was accurately depicted in Angelina Jolie’s directorial film, First They Killed My Father. While politically, they may be on diplomatic terms, each culture views the other as inferior. This can be exemplified when a Cambodian man with Vietnamese roots was beaten to death on the streets of Phnom Penh due to an anti-Vietnamese mob in February 2014.
From a Vietnamese perspective, many had fought to remove Pol Pot from power. To this day, many still experience physical or psychological effects. However, soldiers feel “forgotten,” as the Vietnamese are no longer welcomed in Cambodia with open arms, according to a BBC report.
On a more personal note, Vietnamese families experience blatant racism from the Cambodian government every day. My aunts of Vietnamese descent can never receive Cambodian identification cards, in spite of fluently speaking the Khmer language since they’ve been living in Phnom Penh for over 30 years. The government recognizes them as Vietnamese, so they can never gain citizenship; it is also important to note that Vietnam is the only country which Cambodians uphold this policy.

Celine stayed in Phnom Penh, Cambodia for 6 weeks.