From the banks of the Mekong River in the tiny port of Xieng Kok in northwestern Laos, it is just a couple of hundred metres to Shan state in eastern Myanmar. There, heroin refineries and methamphetamine labs buried deep in the jungle-covered hills supply the addicts of China and Southeast Asia.
Come nightfall and wooden long-tail speedboats travel between the two countries, transporting opium grown in Laos one way while the methamphetamine pills known as yaba move in the opposite direction.
Flowing through the heart of the Golden Triangle, the Mekong is a conduit for all manner of criminal operations. Drug smuggling is the major illicit industry, but other contraband moves along the river too.
"We concentrate mainly on stopping yaba, but guns, cigarettes and petrol are also smuggled from Myanmar," said one 19-year-old Laotian soldier based in Xieng Kok.
Laos does not have the resources to stop the growing of opium in the nearby hills, let alone staunch the flow of drugs in and out of its territory.
"One time last year, they sent a helicopter up and found some fields," said a local farmer named La Te from one of the hill villages. "Then, the government sent soldiers to cut down the poppy. But they only got a little bit."
Nor is Myanmar able to regulate the Mekong. Much of Shan state is off-limits to authorities, dominated instead by rebel ethnic-minority armies funded by by control of much of the drug trade in the Golden Triangle.
Only Beijing can assert any semblance of control over the Mekong. It is even able to influence the Shan state militias, as it demonstrated by putting an end to the piracy that was rampant on the river until recently.
The cue for that was the murder of 13 Chinese sailors, whose vessels were hijacked and used to transport yaba, as they travelled south from Yunnan province to the port of Chiang Saen in Thailand in October 2011.
Beijing demanded an immediate response from its neighbour. Naw Kham, the leader of a gang of pirates based in Tachileik on the border with Shan state and Thailand, was named as the No 1 suspect. He was captured near Huay Xai, a Laotian port further down the Mekong, and sent north to Kunming , where he was executed in March.
"They were an extended gang made up of Burmese, Chinese, Laotian and Thai people. Once they caught Naw Kham that ended them," said Kin Panusee, the skipper of a Laotian cargo boat based out of Xieng Kok. "I never encountered them, but one of my fellow skippers did. They'd pull up alongside in long-tail boats and then jump on board with guns and raid the cargo or demand money."
By handing over Naw Kham, a Myanmese citizen, without a formal extradition request, both Laos and Myanmar were acknowledging that China is the power in the region. "There are no more pirates now," said the Laotian soldier. "The Chinese told the Burmese to stop them."