Yet up until the recent outbreak that began in late May and ended with a cease-fire on July 28, the two countries were still able to manage bilateral military cooperation after the last of the Khmer Rouge insurgency in Cambodia was defeated in 1998.

The agreement is a significant breakthrough to resolve five days of deadly border clashes that have killed dozens and displaced tens of thousands.

After calls by President Trump, the leaders of Cambodia and Thailand are set to meet in Malaysia on Monday to discuss a halt to the fighting.