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

Thai and Cambodian troops clashed in at least six areas along the countries’ shared 510-mile border on Thursday, killing one Thai soldier and nearly a dozen Thai civilians. The fighting—the second instance of armed confrontation between the two countries in almost two months—has sparked fears that the conflict could escalate into open warfare.