The New York Times says:
The top judicial body of the United Nations on Monday sought to defuse tensions at a Southeast Asian flash point, ordering Cambodia and Thailand to withdraw troops from a disputed temple and establishing a demilitarized zone along their mountainous border.
The piece also contains a couple of graphs of helpful background info:
The dispute over the temple has its roots in the period when French colonizers controlled what is modern-day Cambodia. In the early 1900s, French surveyors traced the border line along the watershed of the Dangrek mountain range, but deviated from the watershed at Preah Vihear, placing the temple inside Cambodia. It was an awkward demarcation because of the temple’s location on a bluff more easily accessed from Thailand.
But Thailand’s government made no protest at the time and used the French maps as their own, according to a judgment by the International Court of Justice in 1962. That judgment established that the temple should be inside Cambodian territory. But the ruling did not address the sovereignty of the land surrounding the temple, which is the subject of the ongoing dispute.
Again, here’s my post on the subject from yesterday.