A Thai Navy launch travels at high speed down the muddy brown waters of the Mekong River close to the border town of Chiang Saen in the north of Thailand. To the right is Laos, where huge construction projects funded by foreign investment are rising out of the lush undergrowth along the riverbank and ahead to the left are the dense jungles of Myanmar.

This is the storied Golden Triangle where historically opium was grown to produce heroin for export but where, in recent years, the trade of even deadlier and more profitable synthetic drugs has taken over.

Thailand, Laos and Myanmar are at the frontlines of illicit trade in Asia dominated by transnational organized crime syndicates. The crew on the Thai boat is buoyant following the recent seizure of 6.4 million pills of the banned and highly addictive synthetic drug methamphetamine, known locally as yaba.

few miles downstream at the small town of Houay Xai on the Laos side of the Mekong, border authorities are celebrating their own significant seizure of drugs; the previous night following a tip-off, a military land patrol caught drug mules carrying 500 kilograms of crystal meth. The previous month 7.1 million methamphetamine pills had also been seized in the same area.

The drugs tracked down in Laos and Thailand had originated in illegal industrial-scale laboratories operated by militias and criminal gangs in the remote mountainous jungles of northern Shan State in Myanmar and were being transited through both countries to the Thai capital, Bangkok, but also across Southeast Asia and to distant lucrative markets including Japan, South Korea, New Zealand and Australia.

It’s difficult to calculate with any certainty what quantity of synthetic drugs is being manufactured in Myanmar, but some estimates suggest many hundreds of tons are being trafficked out of the country.