"The U.S. already flunked the test and that should be a wakeup call," a former senior U.S. State Department official told Newsweek.

Fighting along the Thailand-Cambodia border has escalated, resulting in numerous casualties and mass displacement. China attributes the conflict's roots to historical Western colonialism, offering to mediate.

Cambodia and Thailand forces fought each other for the third day over contested territory as the death toll rose to at least 32 as both sought a cease-fire.