...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.
Yes
Thialand (under the reactionary anticommunist Monarchy) has decided in it's material interest to move closer to China
And in doing so has started doing military exercises with China and become a partner in the BRI initiaitive
Thailand also started buying Chinese arms
The boys down in Langley have decided that they can get Thailand to pull out the BRI, disentangle from China and go back to buying US military hardware