...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

p.78

p.79

p.80

p.81

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.