...So you pick up a history book to figure out US's angle
From Peter Dale Scotts: American War Machine-Deep Politics, The Cia and the Global Drug Connection, and the Road to Afghanistan
TL:DR the US turned Burma-Laos and Thailand into a heroin growing triangle (The Golden Triangle) much like they did with the Mafia in Sicily and Marseilles.
The Drug traffickers and drug money became a huge way of CIA to implant bourgeois ideology and suppress communists and the growing popularity of the PRC. They even used ex-Nazis as agents for drug smuggling. It also gave US unfettered access to Myanmars tungsten reserves.
This enitre coalition was directed at China of course.
Maybe. I'm literally just repeating hearsay at this point.