Hun Sen, prime minister of Cambodia, has demanded that Laos withdraw all troops from Cambodian land, threatening war to "protect our territory" if Laos does not pull back posthaste.
Hun spoke during the nomination ceremony of the president of the Royal Academy of Cambodia. "If necessary, I will [fly] to talk about this with my Lao counterpart [Prime Minister Thongloun Sisoulith], but Laos have to withdraw from Cambodia's territory. Cambodia doesn't want war, but Cambodia has to protect our territory."
About 30 Laotian soldiers entered Cambodia, according to Hun, to prevent Cambodia from building a road in Stung Treng, a northeastern province of Cambodia that borders Laos. Laotian soldiers claimed that the road would run through disputed territory.
Hun claims to have repeatedly attempted to contact Laotian leadership over the territory dispute, including an in-person meeting with Sisoulith, but was ignored.
The border dispute is souring relations between Cambodia and one of its closest allies.
"Since April, our Laotian friends have sent forces into Cambodia's territory in the O'alay area of Stung Treng province for the purpose of preventing us from building the road we want to build on our own land. … [Laos must] remove troops from Cambodia without conditions … the ultimatum is that August 17 is the deadline. I give you six days, if you do not want a problem, you remove the force."
Hun added that he had instructed Cambodian military leaders to dispatch troops to Stung Treng and prepare for battle. "We cannot allow anyone to step on Cambodian territory … a friend is a friend, but when a friend steps on our heads, it cannot be. [Commander-in-Chief] Pol Sareoun, [Defense Minister] Tea Banh and [Deputy Commander-in-Chief] Kun Kim have received the order, and if there is an unusual situation that takes place, please do not blame Cambodia."
On Saturday, Hun and other Cambodian leaders intend to journey to the Laotian capital of Vientiane to negotiate the withdrawal of the Laotian forces. The two nations share a 335-mile border, which is mostly unguarded.
The Lao PDR and Cambodia have generally enjoyed a good relationship, with border disputes being the main source of tension. Cambodia has historically been much closer to Lao PDR than to US-aligned Thailand or Vietnam, its other two neighbors, the latter of which it fought a war with in 1978 that resulted in its infamous Khmer Rouge leader Pol Pot being driven from power by Vietnamese forces.
Hun's reign as prime minister, which began in 1985, has been marked in recent years by territorial disputes with his neighbors. From 2008 to 2011, Cambodian and Thai troops skirmished over a Hindu temple in a disputed mountain range along the two nations' border, with Cambodia coming out the victor of the exchange when the International Court of Justice ruled in their favor.
Hun, a former member of the Khmer Rouge, has had less luck with Vietnam, his country's traditional enemy but his political ally. Protests broke out throughout Cambodia in July 2014 when Vietnam refused to apologize for their possession of the Mekong Delta, which both nations lay claim to.